I have a water leak in the OnStar antenna in my 2017 GMC truck with less than 5,000 miles on it. I had the truck serviced at a different GM dealership in town where they located the source of the leak and said water damage is visible in the headliner. Water has been leaking into the headliner and down to the floorboards for an unknown amount of time, but long enough that I can see obvious evidence of water in the A pillar with staining of the headliner. I called Demarois since my truck is a GMC instead of a Chevrolet. The service person told me their only recourse is to clean the staining and dry out the water damage, but they would not replace the headliner on my 6 month old truck because it wasn’t required of the warranty. For a brand new truck, this seemed ridiculous.
I called GMC customer service where I spoke to a very helpful lady in a call center in Michigan who provided better customer service than the dealership right here in Missoula... The lady told me exactly what I knew about my warranty already... This is a manufacturer defect and my vehicle is well within the warranty period. The headliner will be replaced with the leaking OnStar antenna as a warranty service, but I think I’ll take my truck back to the other GM warranty provider in town to have the service completed.