This is a hard one to figure out. I have a 2009 Malibu (non Bose) I installed my X920 bt last week and everything worked great. Yesterday I installed my amp and sub and everything was working great until last night when I left work and put my hi beams on and the radio went nuts. So this is what I get I start the car and everything is good and when I use the hi beams it turns the sound off I still get the beep and it shows the volume going up but no sound. If I go from radio to XM I can get a little sound out of one of the speakers. The only way to get everything back is to reboot the system by turning off the car and restarting. This is what I have found so far if I unplug the RCA;s from the amp everything is good but no sound from the sub. This hole setup was from my other car and worked good. One thing I was thinking was is that the RCA cable that I'm using is just a cheep one for like a home stereo and I also have HID headlights in both hi and low beams. If I pull into my garage and my auto head light come on the same thing happens so that means the low beam will do it as well. 

Ok all fixed. I installed two relay kits for my Hid's and all is working great. I hope this helps someone in the future.