Seriously though, I've thought about getting a vinyl sticker for my rear window which would read "I'm getting over 55mpg. You need to get over it."

Or maybe "Get over it... I'm cruising at over 55mpg."

Or "Please pass to the left... I'm saving gas for your sorry ***."

Or "Hybrid drivers do it soft and gentle."

Or "Get the **** off my *** mother***er!"