Simple and stable rigidbody vehicle movement

I made tank in my game and i made it move front, back and it can rotate left and right i used rigidbody instead of character controller so it can realistically stick to gound depending on higher and lower areas, but it is too glitchy it can filp ower and it keep going foward/back after i stop pushing buttons w or s, i tried whit coliderwheels but it didn't help so can someone just make simple project whit one Cube ( representing a tank) and one simple script that controls that cube and it can go back and foward ( W and S key) and rotate ( A and D key ) and it must sloping depending on the terrain bumps. I think that it will help menj peoples vhit the same problem.

Sory if my eanglish is bad :)