Just bought a 15 XL Denali and trying our best to make it tolerable for our whole family. It's currently at the dealer having the roof cross members looked at/reattached. Going to have them install dynamat to the roof as well. We have the 22 inch wheels with "Brickstones." After reading most of this thread I've decided to go to 20 inch aftermarket rims. My question is are the other tires that are great at eliminating vibration other than the Michelins? We've always liked the all terrain look and were looking at Nitto Ridge Grapplers. Anyone know if these will ride good as long as they're RFB <15 lbs? The main goal is to make this vehicle tolerable to ride in so if the Michelins are the only proven way to help that, I'll sacrifice looks for quality of ride. If those 2 changes don't fix it I'll be looking at getting the exhaust dampeners, and if still not fixed, experiment with the spacers jammed between the roof and the roof rack. Am I on the right track? This was our dream vehicle and our 5th GM SUV so we're pretty distraught about this issue and want/need to have it fixed or at least tolerable. TIA