Wow, awesome first game jam!
Very dynamic. I thought I had made an imba car, and then got very owned on level 4. It would have been nice with some audio, maybe zoom based on velocity so that more of the level is visible if driving fast.
Some weird stuff happening, like the car rolling out of view when going back to build mode, and maybe default values for rotating wheels and a higher force perhaps. Got a little tedious to always assing keys. The ability to resize already existing parts would also be great :)
All in all, very impressive and something to be proud of!