I've had my '02 Grand Prix GT since 2006. Every few months, while I'm driving, the horn honks randomly for a full second. There's no way of knowing when it will happen, and of course it's when I'm in traffic. Last time, I was behind a big dude on a Harley, who of course thought I was pissed at him. Any idea why this happens, or how to prevent it in the future, before someone road rages on me?