you know...
at the end there is shitty ground. it is unrealistic, because shit is supposed to be low-friction
(unfortunately, i am speaking from experience )
here are a few ways you can improve it:
1. add a texture (the car looks stupid right now)
2. the car fells rubbery. to fix that, decrease the density of the car body and increase the density of the underlying frame.
3. make the ride height lower (it is too high)
cool!! i put designer's lambo contach on the place where the waterballs are and drove it off the edge, (made the ragdolls breakable) and it squashed 3 pedestrians!
you should change the control keys, up arrow= forward, lest arrow= counter clockwise, right arrow= clockwise. that would be more similar to most 2d flight simulators.