MO MPG (why I bought the Prius) but my all-time favorite, seen years ago, is: NOYFB (not Prius-specific - strangely it's not available, at least in this state) second place to: WZNTME (on a motorcycle)
License plate would be: "I Think I Can" License plate frame: "I may be slow, but I am in front of you!"
Many states have character limits based on what will fit on a license plate in a large enough font. In my state it's 6 but I think some allow 7.
Mine's not personalized but it is unique. It's a Florida Nascar tag! Had the same tag on my 2007 Tundra Crewmax.
No personalized tags on the hybrids. I'm also one of those that don't like bumper stickers. When I buy the car I have the dealer remove all extraneous decals and license plate frames before I'll take delivery. It isn't that I don't like the dealer, it is that I'm not into giving them free advertising.
I would never have one because of a severe aversion to voluntarily paying extra taxes. But if I did it would say: FOPEC. I do sport this decal on the back of Enzo and my truck. It's good for getting out of speeding tickets! The limits are mostly 55 around here and I drive fast and a lot! Most cops are ex military and the decal works after we chat a bit about old times. 0 points! I'm not driving at insane speeds, just 65 or so on the country highways 'round here.
I dont have personalized plate... but personalized frame. 333 I'm only half evil Because my plate's number is not 666