I can't stand the "My kid is an honor student at FuckMeRunning H.S." type of bumper sticker. To me that's just bragging. You can talk to your kid and be proud of your kid, but to publicly put up signage about how awesome you think your kid is, makes me think you don't have a good grasp on what is important. I wouldn't put up a sign that said, "My kid is captain of the football team/homecoming king/taller than your kid/stronger than your kid/more handsome than your kid."
People generally consider it classless to brag about physical attributes, so why is it any less classless to brag about GPA? It's still bragging. Again, congratulate your kid for her efforts, but don't go printing up t-shirts for the entire family that say your kid had perfect attendance her junior year or stating that she was captain of the debate team because it officially makes you a dumbass. Being humble is a very underrated attribute these days. It's probably why I like those "My kid beat up your honor student" or "My kid impregnated your honor student." bumper stickers. Okay, I've never seen one of those latter decals, but if I had a bumper sticker printing press in my basement, I would seriously consider doing a run of those. Why? Because I am one sick, sarcastic, SOB.