# Swapping the placeholder RX-7 for the real mesh (M1)

Right now every car is a coloured block + a `VehicleSeat` so the game is drivable
today. This is the **one file** you touch to make the RX-7 a real model:
`src/server/CarManager.luau` → the `buildCarModel` function.

Nothing else (saving, the allowlist, car switching, the map, anti-cheat) needs to
change. That's the whole point of isolating model-building in one function.

## Reference photos
The real car's reference photos live on the NAS (too large to commit to git):

```
unraid-1:/mnt/user/data/yy-roblox-games/0-fast-n-furious-sim/001-1993 Mazda RX-7/
```

A single downscaled reference is included at `assets/reference/rx7-reference.png`
for quick lookups.

## Step 1 — Get a model into Roblox
Options, easiest first:
1. **Buy or find a free RX-7 FD model** on the Roblox Creator Marketplace/toolbox,
   or
2. **Model it** in Blender from the reference photos and import the mesh
   (`.fbx`/`.obj`) via Studio's 3D importer, or
3. Commission one.

You want a single `Model` whose parts are welded together, with a clear "body"
part you can drive. Keep the part count low (mobile perf).

## Step 2 — Store it where Rojo/Studio can clone it
Put the finished `Model` under `ReplicatedStorage` (e.g. a `CarModels` folder).
Two ways to manage it:
- **Simple:** keep it in the Studio place file as a real Instance (not synced by
  Rojo). Fine for a single hero car.
- **Version-controlled:** export the model to a `.rbxm` and reference it from the
  Rojo project so it lives in git. See Rojo's `$path` docs for `.rbxm` model files.

## Step 3 — Rewrite `buildCarModel` to clone the real mesh
Replace the block-building body of `buildCarModel(car, maxSpeed, torque, turnSpeed)`
with something like:

```lua
local CAR_MODELS = ReplicatedStorage:WaitForChild("CarModels")

local function buildCarModel(car, maxSpeed, torque, turnSpeed)
    -- Look up a real model by car id; fall back to the block builder if missing.
    local template = CAR_MODELS:FindFirstChild(car.Id)
    if not template then
        return buildBlockCar(car, maxSpeed, torque, turnSpeed) -- keep the old code as a fallback
    end

    local model = template:Clone()

    -- Ensure it has a VehicleSeat named "DriveSeat" welded to the driving body.
    local seat = model:FindFirstChild("DriveSeat")
    if not seat then
        seat = Instance.new("VehicleSeat")
        seat.Name = "DriveSeat"
        -- weld seat to model.PrimaryPart, position it in the cabin...
        seat.Parent = model
    end
    seat.MaxSpeed = maxSpeed
    seat.Torque = torque
    seat.TurnSpeed = turnSpeed

    assert(model.PrimaryPart, "Car model needs a PrimaryPart set")
    return model
end
```

Keep the current block-builder renamed as `buildBlockCar` so any car without a
real mesh still works. That way you can import cars one at a time.

## Step 4 (recommended, M1) — Move to a real chassis
The `VehicleSeat` is great for "it drives today" but for real suspension/grip,
adopt a proven **constraint chassis** (A-Chassis or a modern equivalent). At that
point `buildCarModel` clones the chassis rig and attaches the RX-7 body to it.
Still one function; still no changes elsewhere.

## Verify
- `rojo build --output build.rbxl` compiles.
- In Studio: Play → you spawn in the real RX-7 → it drives → it saves.
- Non-allowlisted test account still can't select the RX-7 (server enforced).