I'm very sure that some of you have done this before but I just tried it today. Provided you have Maya Unlimited 6.5 or 7, you can do this.

1st: Create some kind of obstacle course, environment, whatever you want..

2nd: Create an object like a hover car or boat or whatever.

3rd: Move a camera to a perspective point on the vehicle. Could be helicopter view, cockpit view, whatever.

4th: Parent the camera to the vehicle, just make sure that the vehicle is the parent.

5th: Select the vehicle, go to Dynamics -> Fluid effects -> Ocean -> Make Motor Boat

6th: When you see the locator, select it, press play on the time slider, and use the throttle and rudder sliders in the attributes window to control the vehicle. Voila!

(P.S. Make sure that the vehicle is pointing in the right direction when you use the throttle, or else you'll be driving sideways. This can be fixed easily by pressing playback, observe the direction that the vehicle moves and correct it by using the rotate tool pointing it the right direction. Enjoy!)