- More wheels
The current maximum of 4 wheels is a bit limiting when it comes to more special cars like busses and trucks. This would obviously also need more axles, springs, pins, etc to go with it.
- More spinners
Just like the case for wheels, just a single spinner is also quite limiting. Things like open engines could benefit from multiple moving parts.
- Non-spinning wheels
To clarify, I mean the ability to prevent wheels from rotating while driving. This can enable creators to make more realistic tank threads or ski blades, by having them react to the ground like usual instead of just being a part of the body with an invisible wheel through it.
- Particle emitters
This is a bit niche, but the ability to, for instance, have a large engine emit smoke would be very nice.
Post suggestions regarding RVGL.
There are a few features that I think would allow car makers to really improve their creations. I'll give my own list, sorted on which ones I find most important: