I agree with
Elizabeth and Thomas that an Obama sticker on a Prius is redundant. This morning though, I actually saw a McCain/Palin sticker on a Prius. Upon closer inspection, I decided this was likely some practical joke being played on the Prius owner by friends. I came to this conclusion because the sticker wasn't fully stuck to the Prius, peeling up on one side. It looked like the sticker was peeled off some other vehicle, presumably some large gas guzzling SUV, and stuck on the Prius with half the sticky left.
Also, I saw a car dropping off their child at school with a "Drill Here, Drill Now, Pay Less" sticker. And this was the car:

Yeah, no joke, someone in my neighborhood driving around a $65,000 Lexus Coupe is complaining about the price of gas, through a bumper sticker no less. Maybe if SOMEONE wasn't spending that much money on the car, the price of gas wouldn't hurt so bad.