1) What are some limits for putting things on the same tiles?
2) Is there a ratio of width to length I should keep to?
3) How does armor work?
4) How does enclosing your car work? I heard that a board OR roof OR door means that it's protected by the elements, but don't you need a board and a roof?
5) How do doors work, can they be alone on a tile, or should they have a floor/roof and can I armor plate them?
6) Any tips?
You can see storage capacity by moving the cursor over a container tile while examining the vehicle. The storage capacities are: Stow rack (or whatever. the board that has storage, I've never used one) < box < floor trunk < trunk (650 volume).
1) Generally only one "big" item like engine, gas tank, water tank, etc. fits per tile. The vehicle interface will let you browse what fits on a tile even if you don't have the part available, so you can look over existing vehicles to get a feel for it.
2) I have no idea. Most of mine have been some variant of armored campers.
3) If you put armor plating on a tile, it soaks damage before anything else on that tile gets hurt (mostly). I think solar panels are the exception because they have to be mounted on the "outside," but reinforced solar panels can be crafted.
4) Tiles that are those you mentioned, or that have a roof *and are surrounded by tiles that are inside* count as inside. This is a fancy way of saying you need to make it look like a car... put boards/windshields/doors/quarterpanels on the outside and roofs over tiles in the middle.
5) Place frame (every tile must have a frame AFAIR), place door. Done.
6) You should be fine as long as you don't try anything blatantly insane (all 4 wheels in the same corner!). More than 1 engine is usually excessive unless you're making a base on wheels.
The only non-negotiable part for an operational vehicle is controls and a seat on the same tile.
BY FAR the most painless way of assembling a vehicle is:
Grab a spare shopping cart and enough stuff/the recipe for a vehicle welding rig. When you're disassembling the original vehicles, assemble a temporary immobile solar panel farm with 2-3 panels and the supporting frames somewhere outdoors. Attach one battery of any kind (car, motorbike, storage, whatever) to it. Make sure it's in your reality bubble so it charges the battery while you cut the other cars apart. When you're ready to either start from scratch or rebuild on an existing frame, cut the basket off the shopping cart and attach the welding rig to it, along with the solar-charged battery from your temporary setup. You'll spend literally thousands of battery charges assembling and repairing a vehicle, and you don't want to eat that cost in the tiny individual batteries that power your flashlight and
vibrator PDA.