make sure you do this first...
go into the dual strike software and switch it from FX mode to joystick mode.
then add -joystick to your mame command line or make sure joystick is checked in the controls option if your using mame32. then when you go into a game, tab into setup and find the gas (usually button 1) press enter then step on your gas pedal. it should read the joystick axis.
afterwards if you have problems getting full top speed or a weird dead spot in the middle go back into the dual strike software and adjust the deadzone and range of motion settings.