The only warranty I have voided was anything to do with my gas tank and hoses since they were modified.
My truck goes in every 3500 miles for a check up and change and so far everything has been covered.
The dealership I go to worked with me on making sure everything that has been to the truck is with in my limits but not that it matters now as the truck is past the 3 year warranty.
But it only has 14,000 on it
And I am currently talking with the Good Sam People to make sure if I purchase their program it covers my whole truck.