Two car mistakes

Hello! Im making a car, it can turn and accelerate. But the only 2 problems is that when i turn the wheels when im not accelerating it wont turn, and i want it to keep speed a little longer when i stop accelerating. I kinda understand why it doesnt turn but is there any way to use something to make it rotate and keep speed for a little longer? Im using a base, hinge constraints and a script. Thank you! I will also post this in scripting support incase i would also need scripts.

Video of it: