Press Down to get into the hydraulics setup. You can then press Left, Right, White, and Black to use your switches:

Bouncing: Keep tapping D-pad Down.

Driving on three wheel or other motions: Get your car onto the wheels you want and use the Right Analog-stick to drive backward and forward. Be careful; if your are in three wheel motion decide to lift up the front right wheel from the ground while driving, your car will veer to the right.