This is Mikes idea, and I added the finishing touches to it.
For you street racing fags, its a remote drag tree.It plugs into the cigarette lighter and clips to the visor.You put one in each car at the line, both are operated by a single button wireless keychain remote from a safe distance.To keep both parties honest, each one has an accelerometer, so any foward movement before the green light will cause a red LED to flash, and continue flashing until reset by the remote control, even if power is diconnected.
www.e-m-engineering.com/remote_tree.AVI
And here's the remote(single button one on the left):