I am in the process of suing GM for extensive undercarriage corrosion on my 2005 Silverado 2500 HD. Corrosion began after a few month and within two years, had spread throughout the undercarriage. Not just pale orange. It's flaking red rust, and covers the frame, suspension, and all undercarriage components. No danger of imminent frame failure, but the brakes (the rotors came out in pieces) and the power steering cooling tank have already been replaced (not under warranty, customer satisfaction). They won't do anything else, and the case goes to court next month (after several delays).
Admittedly, I live live beachside in FL, but I have checked hundreds of vehicles in the area, and I can't find anything like the corrosion my vehicle has.
I have deposed GM experts in advance of the court date. They claim that they don't cover any undercarriage corrosion (regardless of severity), that they don't cover any corrosion caused by the environment (isn't that all corrosion), and that they have an exclusion for sea air in the warranty, despite the fact that this exclusion isn't added until 2007. This is all bogus. In addition, they admit under oath that the undercarriage protection is only designed to last for one year, and that they wouldn't have covered the corrosion regardless of where it had occurred in the U.S., how it had been maintained, and how it had been stored. That would apply to the undercarriage and sheet metal.
GM experts have admitted under oath that the vehicle is only designed for a 95th percentile environment and customer. GM experts even asked me if I had taken the precaution of rustproofing my vehicle, despite the fact that the warranty states that rustproofing can void the warranty.
I have also filed a complaint with the NHSTA.
If you have a vehicle that you believe has experienced premature corrosion, please email me at [email protected].