From Jack 3:
They can't do that. Check the Magnusson-Moss Warranty Act of
1975. They must provide, in writing why they are denying
coverage. The can only deny coverage if the parts that you
are trying to have covered, are directly effected by any
modifications you made. In other words, if you go in to have
a warranty problem with your AC looked at, they can't deny
you coverage because you have a lift-kit on it.
Mention the Act, which is regulated by the Federal Trade Commision, to them, and see if they catch your drift. Most dealers are either ignorant of the law, or they simply try to intimidate people.
From Bernd Ratsch:
http://www.sema.org/warranty
If the dealer gives you any more crap, contact SEMA, open a case, get the number to call the FTC, and have them take care of the dealer phone calls. We had a '99 R/T fixed under warranty, regardless of the shift-kit, Powerdyne S/C, modified TB, headers, and other "bolt ons". Yes, they refused and even "Black Listed" the truck. The FTC took care of that and now they sing a different tune
From Jason Yates:
Poking around the SEMA site, I also found this site (which is "Powered
by SEMA") with some good info:www.enjoythedrive.com. Click on the "Your car and the law" tab (right-hand side).