"Honk if your horny"

Yes, that's right, if "your horny." It wasn't my idea, I saw it soap-sticked onto the back of a Grand Prix being driven by some high school girls down Lakeway Road. I'm not really sure what it meant but it struck me as a.) funny b.) sad and c.) an indictment of our education system (or at least teachers doing any sort of editing) that these girls either didn't know or didn't care that their grammar was beyond atrocious.