Is it only when your car is flipped? I designed it so that when your car is flipped no linear or angular velocity can be applied to the vehicle, so you can't just drive around upside down.
No- right at the start; I press enter, [s] reverses but really slowly, [w] gets me to go faster (and shift even more so), but [a]/[d] turn me at about 2deg/second - so I can almost get a 90deg turn by pressing pressing [w] then [a] then [w], etc. but just holding [w]+[a] takes me into the nearest wall… :/
(Just tried v3, still persists).
Ok, I can't really explain why the reverse is slow, because it should be half the velocity of going forward. For your second issue, I also configured it so that pressing only A and D without W turns you slowly because it resets angular velocity, while pressing A or D with W does not. This is because I noticed that turning with A or D alone will immediately flip the vehicle, so often that it becomes boring, because you are immediately applying torque to a rigidbody with no forward velocity, and based on physics, that just simply flips the rigidbody.
If you think its more fun to allow the player to retain angular velocity while just turning, I can put that back in. But for me, having my car flip by taking a small corner every time sucks.