Can I make a motorcycle? If not then I suggest that you can. 
RV type vehicle. Maybe easier to code if the interior was a separate map. Maybe?
I used to code on muds. I’ve been looking at the source to see how different it is. Not that different actually.
Motorcycles are in. Rvs not so much.
RVs. Totally used in walking dead! 
Already in as a random (and likely) find in parking lots and garages, as well as homemade, if you’re that hard up for one.
RV type vehicle. Maybe easier to code if the interior was a separate map. Maybe?Separate maps (especially mobile ones) are nigh impossible with the map system Cata uses.
I used to code on muds. I've been looking at the source to see how different it is. Not that different actually.Except they have a map system designed for multiple z-levels, (or are without a map at all if it's a text-based one,) which puts the problems in different categories.
Cata/DDA needs a massive map system overhaul for a lot of the suggestions that come about, and I have no idea if it’ll happen.
The code thing was more about me thinking about getting back into coding. It’s been a number of years. I used to help administer a mud. And yes, we had an outside/overworld map that looked much like a roguelike. The mud I worked on was called Core. It’s still around. The Semi truck which I found has all the pieces I imagined for an RV. Though I suppose the TV also has a water reservoir. I can get over not having that part of it. The Semi-Truck makes me want to add a living are on the back of it.
I need to adjust the vehicle code to allow vehicle tiles that aren’t difficult terrain.
The funny thing is vehicles basically are independent submaps that move around on the regular map.
Really? I was under the impression it dynamically modified the terrain itself.
It’s kind of crazy, everything that cares about the value of a terrain square calls through a function that checks whether there’s a vehicle there first, and only if there’s no vehicle it returns the value of the terrain.
EDIT: Oh I didn’t mention the caveat, it’s a moving map, but it doesn’t carry things with it except as a special case. Currently this means trunks/boxes and passenger seats. Wouldn’t be too hard to allow walking around in a moving vehicle, if there were some kind of mass-transit-like thing this would be do-able… that might be fun…
Non difficult terrain and then add flooring.