It works, it really works!
Growing up, I always wondered why golf balls were dimpled and I was surprised to learn the answer. It's not obvious, but the dimples help the ball travel farther and longer by creating chaos in the wind stream, which cuts down on the tail (watch the video for a great visual explanation). And then I wondered why we didn't see it more often, say on cars?
I always assumed the dimple effect only took place at higher speeds. Either that or it was just plain ugly.
Turns out Mythbusters thought the same thing (via Autoblog). They took a Ford Taurus and covered it with dimpled modelers clay.
The video for the episode is from megavideo:
So, why not do this to a Prius?