Originally Posted by Bonemaro
This may or may not help. It is straight from the manual so it has credibility.
This allows me to clarify another point on warranties. If GM didn't make something that broke, GM won't fix it. For example:
The steering wheel that you installed in your Caprice in the original post breaks. You take it to your dealer. Your dealer tells you that GM does not fix non-GM parts. You call the manufacturer of the steering wheel. They fix it.
If you install a non-GM part on your GM car, then GM is no longer responsible for that part of the car. That means that a bad install on your aftermarket exhaust is not GM's responsibility, nor is it GM's responsibility to make sure that the aftermarket exhaust passes inspections of any kind. If your aftermarket part goes bad at any time, GM has no obligation to cover it.
In addition, any aftermarket part that causes an OEM part to fail has voided the warranty on the OEM part. For example, throwing a Duramax in your Camaro but not upgrading the transmission is a risk that the transmission can't handle the new engine. When the transmission fails from this mismatch, the owner is responsible for repairs.
Does that clear this up a little more?