Brent, sorry im confused, which harness did you end up using? PAC or Metra?
if PAC theres not much you can do i think, but if you're running the Metra theres a little screw on the side that you can use to adjust how loud you want it, just turn it down a bit and it will be fine, i had the same problem.
Tom, i dont have that problem, only problem i have with mine is sometimes after removing the key with the door opened, the chimes (key left in ignition with door open chimes) dont stop until i put they key in and then remove it, no turning required. other than that the GMOS is perfect
2005 Phantom GXP - Stockish