Yeah, I'm a ham too. Neat item, DO NOT BID ON IT unless you're licenced. The FCC DOES track things like this and you'll get bitch slapped with a fine for even ordering it. But it is a good way to have fun with traffic.
That's pretty cool! Can't you build your own FM transmitter, but with MUCH lower power, and run it without a license? I thought you could have broadcast influence for like 50 feet or something without needing any permits. Something small like that would still work with your buddies at a car show.