Vehicle Base is a small VMF containing an easy to edit base for creating physics vehicles. The groundwork for the user controls, the logic_compares, game_ui, and prisoner_pod entities are all there and ready.
Pressing any of the mappable controls (forward, backward, left, right, attack, and attack2) will turn on sprites in front of you. All you have to do now is remap the controls to do other functions instead of turning on the sprites.
This file also contains the source VMF for Source Chariots.