From the dealers I have talked to: "no specific part with void your wtty. But, any specific aftermarket part installed will void "that portion" of your wtty." So what I have understood from conversations with them is that if when I installed my short throw shifter, I have voided the wtty on my shifter, obviously since it's no longer on the car and the new one is. However, I may have also voided anything else transmission or shift linkage or basically anything else they can pin on my messing with the shifter. For example when I had my first free oil change service done, I asked them to look into a clunk I was feeling in my drivers seat when I would corner in a more "spirited manor". They came back to me and some how were trying to pin it on the Steeda K member brace I had installed because when they lifted the car the tech heard a popping noise from somewhere under the car, and could find nothing with the seat itself. He supposedly tightened one of the K member bolts 1/8 turn, set the car down and lifted it again and the pop did not occur. Then since this was not a factory part he had touched, had to charge me $139 for his diagnostic.... So my "free" service was no longer free because of an aftermarket part I had installed that had absolutely nothing to do with the problem with my seat. I refused to pay and told them I would test drive the car and when the seat still popped, which it did, I was not paying squat! So I left with my "free pain in the ... service" and will not be visiting that stealer ever again. So in short, IMHO dealers will and have done anything possible to get out of wtty work. Best of Luck!!