Gravity Tailgate Racer Contest

A long time ago, I remember a contest where we'd build wooden toy cars (generally using kits). Competitors would all place their car on top of a hill, then they'd fall down. The winner was the one whose car reached the end fastest. Techniques like intelligent placement of weights and smart aerodynamics improved a car's ability to win.

So, I propose a secondary event using the same vehicles and hill. A strip of inflexible plastic (or metal) of approximately car height would be in each track with a motion camera attacked to its front. The strip would be attached to the track in such a way that it could be moved down the track quickly. The motion camera would be used to select a speed which minimized distance between the device and the car without them touching. I believe such a solution would likely end up reducing the advantage of having an aerodynamic design.