we had a salesman at one shop buy a cd changer and didn't want too or could not install it himself and didn't want to pay us to do it and of course wanted it during shop time. It was slow that day and I had a little extra time, and an extra keyless entry left in the bay so I wired one button to honk the horn, the other to open his sunroof. I Followed him home that night and he thought a mom in a minivan was going to get out and kick his ass after I happened again at the next light. He was not sure what was up with the horn but when the sunroof opened on his own he started to put it all together. Not sure if that one of the time I wired an alarm siren into another guys tail lights is my fav trick I got to do, they were both good for a really good giggle but the lesson here is don't piss off the installer and/or give him your car on a slow day.