I got behind a pair of these on the way home from work yesterday. I didn't think they allowed these things inside the Austin City Limits, but I guess I was wrong. I mean, the only time I've ever seen any on an actual vehicle was in a restaurant parking lot in Kansas and driving home from Lago Vista (where there were a LOT of McCain/Palin signs in yards...related? I think so).
The pair I saw yesterday were HUGE and shiny chrome on the back of a Ford F-150 King Cab. I kept trying to get up next to the guy (girl? I hope not...) to see what he looked like, but no such luck. I'll bet you a dollar he was alone, though.