ya i have i have a set of GXP headlights in my car. went past the 9012 upgrade cause i couldn't find the bulbs for cheaper than $25 each so i went with HID'* from http://www.ddmtuning.com/
. and ordered some extra bulbs for back ups. got the 9006 kit in 5000k and the 880 fog kit in 4500k awesome light output and when i use theo lows and highs together it is extremely blinding. although when you hit your highs it will just be those. for some reason when GM designed the electrical system for the GXP the set the DRLs to lows and when ya hit the highs the lows shut off. also did a poor job on the wiring for the GXP fogs.