The Main Approaches
M1 interior builds fall into four main categories: 80/20 aluminum extrusion (the most popular DIY route, modular, no permanent modifications, uses the M1's 440+ feet of built-in T-track), wood/2×4 framing (cheapest, strongest, heaviest), Tune's factory interior kit (pre-designed panels, easiest, ordered with the camper), and Vecel Outdoors' X-Series (third-party drop-in systems purpose-built for the M1). Most owners combine elements from more than one:
| Approach | Cost | Weight Added | Flexibility | Best For |
|---|---|---|---|---|
| Tune Factory Kit (beta) | ~$1,500–$3,000+ (TBD) | Lightweight (TBD) | Low, fixed layout | Owners who want a done solution at order time |
| Vecel X-Series | ~$5,005–$5,445+ | Varies by layout | Low, fixed layout | Owners who missed the factory kit window or want a more built-out system |
| 80/20 Aluminum | ~$300–$800 DIY | ~15–40 lbs | Very high, fully reconfigurable | Iterative builders, tech-minded owners |
| Wood / 2×4 Builds | ~$100–$400 DIY | ~20–60 lbs | Medium, cut-and-build | Budget builders, owners with shop access |
| Hybrid | Varies | Varies | High | Most experienced owners |
Build Sequence: What to Plan First
This is the most important section for owners who haven't started yet. The order matters because some things are hard to change after the fact:
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Truck bed prep (before M1 arrives)
If you're adding a DECKED drawer unit, bed liner, or truck bed reinforcement, do this before the M1 is mounted. Accessing the bed floor under a mounted M1 is awkward at best. Tacoma owners: install your bed stiffeners now if you're running them. See the setup guide for Tacoma bed stiffener info.
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Electrical plan
Decide where your battery will live, how the DC-DC charger connects to the truck, and where cables will route before you build anything. Running wires through a finished build is miserable. Battery in the M1 interior vs. in the truck bed behind the cab vs. under the DECKED drawer, all are valid; all require different cable runs.
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Floor and structural frame
Floor surface (BedRug, plywood, mat) and any structural frame (DECKED, custom platform) go in next. These are the foundation everything else attaches to.
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Fixed infrastructure
Mount the battery, inverter, DC-DC charger, and fuse block. Run all primary wiring. Install any heater bracket or water tank mount.
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Shelving and storage
80/20 rails, wood shelves, drawer slides, and overhead storage come after electrical is in, so you can route wire management through the structure.
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Finishing and accessories
LED strips, 12V outlets, USB ports, small accessories. These come last because they're easy to move and add.
The most common regret in the M1 community: building the storage system first, then trying to fit the electrical into the leftover space. Battery, inverter, and DC-DC charger are large, heavy components. Reserve space for them deliberately. Don't figure it out after the shelves are in.
Floor Systems: DECKED & BedRug
DECKED drawer system
DECKED is a truck bed drawer system that mounts to the bed rails and installs before the M1. It creates two waterproof, lockable drawers that slide out from the rear of the truck, accessible even with the M1 mounted. The M1 then sits on top of DECKED's plastic deck surface.
DECKED is arguably the most-discussed interior topic in the M1 community. The strong interest reflects a genuine tension: DECKED is extremely useful but comes with a real payload cost.
What the drawers are typically used for
- Recovery gear (hi-lift jack, traction boards, tow strap, shovel)
- Diesel heater fuel bottles and heater components
- Tools and spare parts
- Water jugs (accessed without opening the camper)
- Propane canisters and camp stove
- Gear you want accessible before you set up camp (chairs, firewood)
M1 + DECKED fitment
DECKED installs in the truck bed and the M1 mounts to the bed rails above the DECKED deck. The M1's mounting hardware is compatible; DECKED's deck surface doesn't interfere with the M1's standard bed-rail attachment points. The main consideration is ride height: DECKED raises the floor of the M1 by a few inches, which slightly changes the standing/kneeling height inside. Most owners find this negligible; taller owners in already-height-constrained configurations should note it.
BedRug
BedRug is a molded carpet-like bed liner that covers the truck bed floor and sides. It's softer, quieter, and warmer than a spray-in liner. Tune's factory interior kit requires BedRug as the base layer. For owners not getting the factory kit, a BedRug is a popular DIY choice for the M1 floor. It's comfortable to kneel or sit on, provides thermal insulation from the metal bed floor, and is easy to clean.
BedRug price: ~$300–$500 depending on truck and configuration.
Simple plywood platform
Many owners build a custom plywood deck over the truck bed floor as the base for their interior build. 3/4" Baltic birch plywood cut to bed dimensions provides a flat, solid surface for mounting 80/20 uprights, drawer slides, or other components. Finish with a non-slip coating or cover with a rubber mat. DIY cost: $50–$100 in lumber.
Structural: 80/20 Aluminum vs. Wood Builds
80/20 aluminum extrusion
80/20 (T-slot aluminum extrusion) is a modular frame-building system. You cut rails to length, connect them with corner brackets and bolts, and build frames that hold shelves, mount panels, and organize gear. The key advantages for M1 builds:
- Reconfigurable: unscrew, move, rebuild. No sawdust, no new cuts.
- Strong and light: aluminum extrusion is much lighter than equivalent wood for the same structural load
- Integrates with the M1 T-track: the M1's built-in T-track uses M6 hardware, compatible with 80/20 accessories
- Clean look: many owners find the industrial-aluminum aesthetic appealing
The main profiles used in M1 builds:
- 2020 profile (20mm × 20mm): lightweight, good for shelving and organizers with moderate loads
- 4040 profile (40mm × 40mm): heavier-duty structural frame work
- M8 4545 profile: the community-preferred heavy-duty extrusion for load-bearing anchor points ("waaay better" per community posts)
Where to buy: 80/20 Inc. (direct, expensive), Misumi (cheaper, slow ship), or local industrial supply. McMaster-Carr carries compatible hardware. Budget $4–$10+ per foot of rail depending on profile and source.
Wood and 2×4 builds
Wood builds are cheaper, more accessible, and feel more "cabin-like" than aluminum. Standard 2×4 construction lumber or finish-grade plywood from any hardware store. Baltic birch is the preferred material for visible surfaces (it's strong, void-free, and takes finish well. HDPE (high-density polyethylene) sheet is popular for countertop surfaces) it's waterproof, easy to clean, and food-safe.
Advantages of wood builds:
- Cost: a complete interior in wood often runs $150–$300 in materials — dramatically cheaper than equivalent 80/20
- Warmth: wood reads as cabin, not workshop
- Familiar tools: most people can work with wood; 80/20 requires specific hardware and some system knowledge
- Custom shapes: easy to cut to non-standard angles
Disadvantages:
- Heavier than equivalent aluminum structure
- Harder to change — you're cutting and screwing, not unbolting
- Moisture risk: repeated wet/dry cycles cause warping; seal all surfaces
Community insight: Many experienced M1 owners who started with 80/20 rebuilt in wood after their second or third iteration, and many who started with wood wish they'd used 80/20. The "best" choice depends on whether you're the type to constantly optimize your build (use 80/20) or build it once and be done (use wood). Both approaches are well-documented in community builds.
Tune Factory Interior Kit
Tune offers a factory-installed interior kit that must be ordered with the M1; it cannot be added after delivery. The kit is currently in pre-release / beta, so detailed specs and final pricing are limited. What's confirmed so far:
- BedRug floor covering
- Basic cabinetry / interior panel system
- Fold-up bench, converts the floor area into a seating layout when stowed
- Designed to be very lightweight compared to a full DIY galley build
The factory kit has a first-60-days discount: order it within 60 days of placing your M1 order to get the promotional pricing. After that, pricing goes to standard.
Who the factory kit is right for:
- Owners who want a done-for-you interior shipped with the camper
- Payload-constrained builds where the lightweight design matters
- Anyone who wants to get camping quickly and optimize later
Who might skip the factory kit:
- Owners with specific electrical or storage requirements that conflict with the factory layout
- Builders who want the freedom to redo things as they learn what they actually need
- Anyone who needs a fully-built galley today (Vecel below is the production alternative; the factory kit being in beta means specs and availability may shift)
Heads up: Because the factory kit is still in beta, weight, exact contents, and pricing are subject to change. Confirm specifics with Tune at the time you order.
Vecel X-Series Interior Systems
Vecel Outdoors makes purpose-built drop-in interior systems specifically for the Tune M1. Unlike Tune's factory kit (which has to be ordered with the camper), the Vecel X-Series can be added at any time, which makes it the main "done-for-you" option for owners who skipped the factory kit at order time or who want a more built-out galley than what Tune offers.
Current X-Series layouts:
- Summit A, from $5,445. Galley layout with cabinetry, drawers, and an integrated countertop with cup/jar cutouts.
- Summit B, from $5,445. Mirrored galley variant with a slightly different storage and counter arrangement.
- Ascent A, from $5,005. Lighter-cost galley layout with similar cabinetry but a simpler drawer configuration.
All three are pre-engineered to fit the M1's interior dimensions and mount via the M1's existing T-track, so install does not require permanent modification to the camper. Pricing is significantly higher than a DIY 80/20 build, which is the main tradeoff: you're paying for finish, fit, and the time you don't spend building.
Who Vecel is right for:
- Owners who didn't order the Tune factory kit and want a comparable done-for-you interior post-delivery
- Owners who want a more substantial galley than the factory kit (more drawers, integrated counter cutouts)
- Anyone who values finish quality over reconfigurability and is willing to pay for it
Who might skip Vecel:
- Payload-constrained builds where the kit weight is hard to absorb
- Builders who want full layout flexibility (80/20 stays the right call)
- Tight-budget builds (DIY 80/20 or wood is dramatically cheaper)
Electrical Integration
Electrical is where M1 builds get complex, and where the most mistakes get buried inside finished walls. See the dedicated battery guide and solar guide for detailed specs. A few interior-buildout-specific considerations:
Where to mount the battery
Three common placements:
- In the M1 interior, cab-end wall, most common. Battery lives in the camper, close to the DC-DC charger cable run (shorter cable run = less voltage drop). Takes interior living space but is easy to access and service.
- Under DECKED drawer: puts the battery below the M1 floor level in the bed. Excellent for freeing interior space; requires longer cables through the DECKED structure.
- Behind cab in truck bed (no DECKED), battery sits in a dedicated box against the cab wall, under the M1. Accessible from outside but requires careful waterproofing.
DC-DC charger placement
The DC-DC charger (typically a Renogy 40A or Victron Orion) charges the M1 house battery from the truck alternator while driving. It mounts between the truck's starting battery and the M1 house battery. Most owners mount it in the M1 interior near the house battery, running a cable through the truck cab firewall or under the truck to the starting battery. Plan the cable route before the interior is built.
12V outlets and USB ports
Panel-mount 12V outlets and USB-A/USB-C ports are easy to integrate into wood or 80/20 panels. Common placements:
- Headboard area near the sleeping platform (phone charging at night)
- Mid-level shelf (fridge power, laptop charging)
- Near the barn doors (easy access while seated in the tailgate area)
Shore power (AC) inlet
If you camp at hookup-capable campgrounds, a shore power inlet allows you to plug into 120V power and charge your battery bank or run AC devices. Typically mounted on the exterior of the M1 (requires drilling) or run in through a canvas window with a weatherproof pass-through. Shore power significantly changes the battery sizing math for any high-draw devices (AC units, induction cooking).
Storage Solutions
DECKED (see above)
The under-M1 drawer system, the highest-engagement storage topic in the community. Best for heavy gear you access frequently but don't need inside the camper.
Side shelf/storage units
The most common interior layout: a structural unit on one side (typically driver's side or passenger's side) that runs from the cab wall to near the barn doors. This unit typically contains:
- Lower section: 12V fridge
- Middle section: drawers for clothes, food, or gear
- Upper section: shelves for items in use
The opposite side is left open for the sleeping platform to fold down, gear to lay flat, or a dedicated kitchen area.
Overhead storage
When the pop-top is deployed, there's usable overhead volume on both sides of the elevated section. Shallow shelves or nets mounted to the M1 side walls (using the T-track) store lightweight items overhead. Clothing, rain gear, toiletries. Weight limit is low for overhead storage. keep heavy items low.
Magnetic mounting
Rare-earth magnets attached to aluminum panels create convenient no-drill mounting for frequently-accessed small items. Popular for kitchen tools, multi-tools, headlamps, and similar small gear. The magnetic panels can themselves be T-track mounted and repositioned.
Elastic bungee net / mesh pockets
Simple, lightweight, zero-tool storage. A large mesh bungee net across the cab-end wall or cargo net straps across shelves keep lightweight items from shifting while driving. These are often the last thing added but disproportionately improve day-to-day usability.
Sleeping Platform
The M1 sleeping area is determined by the pop-top you ordered (mid vs. full platform):
- Mid platform: approximately 60" × 72" sleeping surface
- Full platform: approximately 60" × 78" sleeping surface
The sleeping surface is the M1's platform itself, the platform is standard equipment and doesn't require DIY work. What owners customize:
Mattress
The mattress is not included in the base M1 price. Tune offers a Hest mattress as an optional add-on, or you can source your own. The platform dimensions are 60" × 72" (mid-size) or 60" × 78" (full-size). Popular options:
- Custom-cut foam: 3–4" high-density foam cut to exact platform dimensions. Significantly improves sleep quality over the basic Tune foam. ~$100–$200 from foam suppliers.
- Latex foam, more comfortable and durable than standard polyurethane foam; heavier. ~$200–$400 for custom cut.
- Folding mattress: some owners use a foldable mattress that stores compactly during the day.
Sleeping platform access
In full-time use, you're climbing up to the sleeping platform via the fold-down ladder. Some owners add a grab handle mounted to the M1 frame near the barn door opening to assist with the climb. 3D-printed grab handle mounts for the M1 T-track are available from the community (Printables).
Sink & Water Integration
Water systems are covered in detail in the water guide. For interior buildout purposes:
- Fresh tank placement: typically under a shelf or in a dedicated storage area. Gravity-fed systems work with the tank at or above sink level. 12V pump systems allow the tank to be anywhere.
- Sink drain: in the M1, the simplest approach is a grey water bag under the sink rather than a through-hull drain (which requires cutting the M1 floor). The grey bag is emptied periodically.
- Countertop cutout: if integrating a sink into a wood counter, HDPE is the preferred surface material. It's waterproof, food-safe, and easy to clean. Standard undermount or drop-in RV sinks work in custom HDPE countertops.
Weight Management: The Hardest Part
Interior builds have a way of accumulating weight quickly, and the M1 is mounted on a truck with a fixed payload rating. Understanding your constraints before you build is critical.
| Component | Typical Weight | Notes |
|---|---|---|
| M1 (base camper) | ~400 lbs | Before any accessories |
| DECKED drawer unit | 177–233+ lbs | Truck-size dependent (mid-size ~177; full-size 220–233+) |
| 100Ah LiFePO4 battery | ~25–30 lbs | Per battery |
| Inverter + DC-DC charger | ~10–15 lbs | Combined |
| 12V compressor fridge (25–45L) | ~20–40 lbs | Plus food weight |
| Water tank (5 gal full) | ~45 lbs | Water is 8.3 lbs/gal |
| 80/20 interior frame | ~15–35 lbs | Depends on scope |
| Wood interior frame | ~25–60 lbs | Depends on scope |
| Portable AC unit | ~17–31 lbs | If running A/C |
| Gear, food, clothing | ~50–150 lbs | Highly variable |
Add these up for your specific configuration and compare against your truck's remaining payload after the M1 is mounted. The payload guide explains how to find your truck's payload sticker and calculate available margin. The builder tool lets you model specific items.