Excellent concept! I have one on the back window of my Bigfoot
However, I will warn you that the outfit that produces them - Cafe Press - will hound you mercilessly forever after, with offers of 10% off, 25% off, super special of the day, see this coffee mug - how about this T-shirt etc" (none of which have ANYTHING to do with fiberglass trailers!).
Cafe Press can make you wish you had never bought the damn sticker, unless you mark their incoming e-mails as "spam" and add their address to your "block list" after you actually GET the sticker.