I've got 35,000 on my 16 ED. I can buy a warranty for 3500 that will cover me for another 4 years and up to 85000 miles. They tell me that if I don't use it I get the money back?? I just had the AEM done and I want to do the GDE. Do I get the warranty, or is that a waste of money? I just don't want it to throw a rod at 36001 and be crying. I'm assuming that the GDE won't ruin my warranty?