Im not having any trouble...
Rovers suck if you dont put any effort into designing them. Make a wide, long chassis and low mass center. If low enough, even the grey wheel brakes won't tip you over. If you dont wanna control the SAS with the same keys as the wheels, remap your keys. I control wheels with numpad, SAS with wasdqe. Like cicatrix said, if you're using the grey wheels you might wanna disable front brakes Sorry its just about the 1000th post that i read about bad rovers...