Add me to the Vibration Nation. Long story short, wife said "I know you're ready for a new truck so go ahead and start looking. Had my truck in getting the tailgate assembly fixed and saw a 2015 C20 edition on their showroom floor with a very hefty rebate. Worked with them for a few days until we got to an agreed upon price/trade. So, at around 4-500 miles or so, I started to notice a vibration at freeway speeds. Worst seemed to be around 70-75. Took it in and they checked everything and said, "we got it better but there's on tire out of balance". They ordered a tire and replaced it two weeks later. Took it in and they replaced it and said "good to go". Picked it up and headed home and it was clear the issue wasn't resolved. At this point I'm starting to get PO'd. Got a call to go pick up my plates and sat and talked with the sales manager about my issues. I told him I hadn't spoken with the service department because I hadn't yet cooled down enough and going in full rage wasn't going to get me anywhere. He was not pleased and said he'd be in touch in a day or two. Called and told me to schedule a drop off, they'd get it fixed. Anyways, this time they had it for 3 days and did some sort of Pico??? test and sent the data to GM engineers. I'm now in the waiting process for GM to get back with service. I'll keep everyone posted.