Catcalling while driving?

I want to know if any woman encountered the same problem. First time I got honked on the freeway and a car with a middle aged white guy blew me a kiss. Then he hand signaled me trying to get my number or smthg, and followed me for awhile. Second time in sunnyvale where I was at a traffic stop. A black guy next to me honked me again and gave me a heart shape hand sign. I dont really have anything on my car, no stickers or anything for triggering actions like that. I need to know if this is some kind of new scam or crime happening in the bay? Could it be he saw my snowboard at the backseat and wanted to rob me?