Professional logos on vehicles
When I worked as a consultant, the company was thinking about paying anyone in the company who would paint the logo on their car. No takers. This was in the Boston area, and I wasn't about to give up honking at other drivers or opening my window, extending my arm, and "communicating", which might hurt the company image if I have their logo all over my car.
BTW, I'm not gennerally an angry or aggressive driver. I just wish people would use those turn signals.