Depends on your dealer. Some dealers don't mind mods; others look for any technicality to get out of warranty service. You should know the law is that the modification has to CAUSE the failure for warranty service to be denied. That's the Magnuson-Moss Act, I think it's called.
If you're very concerned about warranty, all you could do is cosmetic stuff, maybe some suspension mods, and maybe a cat-back. Some sure-fire ways of voiding the warranty would be forced induction, long-tubes, a tune, gears, cam, and sometimes CAI.
nothing voids the warrany unless they can prove the that "mod" caused the problem.. if it did not cause the problem they have to fix it.....
While that may sound good the reality is most bolt ons will ultimately require some sort of tune in order to get the most out of them. The tune alone could void the warranty. I'd talk to your dealer and do a little research first.
When it takes more than a sweet mullet to prove you rule at the trailer park
A tune can not void your entire warranty. If you had a tune then the dealer could void portions of the Power train warranty I.E.-engine, tranny, etc... But if you had a strut crap out then they would have to repair it under warranty because a tune isn't gonna effect a strut, etc. But even then like most people have said it depends on the dealer and who works there. I would shop around different dealers around you service departments and ask the service manager himself about mods and his dealerships view on it. You always need one service department you like and if you move you find another. It's like a doctor for you. Hell the dealer I use for service I would never buy a car from because I hate there way of business, but my service needs would always go to them.