[CIWS]

All that sucks dude. It's the one of the reasons someone coined the term Mod Hell. You're actually a good example for others who are considering purchasing aftermarket mods or add ons for their car. If the parts and work are not done by the dealership they can use it as an excuse to deny warranty work related around the changed part. That part may or may not have anything to do with your problem, but they have the right to deny work around it. You either have to find a dealership willing to do that or replace the OEM parts back on to the car before giving it to the dealership to have work done. The suck thing is once they see Modded parts on the car they know things have been done to it. Mods are cool but they can become a pain when it's time for something to be handled under warranty, depending upon dealership. Plus with GM getting strapped for cash the restrictions will only get worse.