And by interesting I mean annoying!
I installed a set of 05 mirrors into my 2000 with the markers/turn signals and when I have the engine running a loud buzz comes from the center of the dash. It sounds like it comes from the relay box that is kind of under the radio.

The only time it stops is if I adjust the mirrors to the right or down or if I have either turn signal or hazards on. I currently have the mirror adjust disconnected, soon wondering if there is a ground issue since the ground for the lights go through the ground on the mirror motors.

But other than the noise, everything works perfectly, turn signals, markers, window motors all work fine. Any ideas?