Bumper stiker politics are truly an US speciality, at least judging by the quantity of cars on the road with bumper stickers, most of which reflect an appaling lack of originality or even thought of any kind: "support our troops" (how? why?), "united we stand" (for what?), "proud to be an American" (why? ever been abroad? have any idea at all about the rest of the world?), or the inevitable "911 terrorist hunting permit". There are, however, some really nice exceptions, at least on the internet (I have yet to see them on an actual car). Some rather original ones can be found on the Scott Horton section of the website
Liberty Stickers.