I leased a 2015 Yukon SLE Thanksgiving weekend. I have had the thumping/interior pressure issue that has been mentioned in this forum. It has now been at the dealer for 8 days. I've spoken to the tech on two different occasions and he is at a loss. They have not been able to contact GM tech assistance due to the Christmas/New Years holiday. He did tell me that there is a service bulletin on the Noise Canceling mic, that didn't work. He was going to take the headliner down to check the roof struts today. They have thrown a different set of wheels/tires on it, checked the alignment, suspension, etc. If anyone has any other ideas or suggestions that I can give to the tech, please let me know. Its a 7/2014 build date, 5.3L, SLE with 20" polished wheels, no moonroof or roof rack cross members. It has running boards and the dealer installed Leather seats and the chrome accessory kit on it before I leased it.