Fucking sweet.
On a smaller scale, some of the people we know at the local Honda stealership played a little joke on one of their co-workers recently...
They kept him busy on the floor for a couple of hours, meanwhile a couple of the techs took his bike round back, pulled off all the plastics and rigged up some HOT PINK LED's (with a remote control). They managed a 4 hour job in 2 hours.
So he left work, pulled out onto the road and they hit the remote... it wasn't till he was a ways down and stopped at a traffic light (it was dark) that he noticed.
He had a good laugh about it, and has since removed them, offering the full LED kit to anyone else who wants to play a similar prank on their friends.