The movement feels bad with its fast deceleration when the keys are let go.
The only things that affect movement is this:
What just happens is when A or D is pressed then the car turns to the left and right. A and D keys also gives a force moving forwards when pressed. This all happens simultaneously.
Also when both A and B keys are held at the same time then it gives a boosted force forward.
I tried using linear damping to make it decelerate slower but not helping (I think) .
Here is also the object behaviors if it can help:
