FirsttimeGMCbuyer

I recently bought a 2015 Yukon XL, and like most others on this forum, I have had the terrible experience of the cabin pressure and loud noise at speeds between 40-45 mph and around 70 mph. I took it in to the dealer the day after I bought it highlighting the issue, and after saying they had never heard of something like this (of course), they then determined they didn't have the expertise to fix it properly. They sent it to a local body shop who did the repair outlined in the GMC technical bulletin, and then called me stating "everything is fixed." I picked up the vehicle, and of course nothing was fixed. I gave it back to them and they have had it for over a week now doing God knows what. In the meantime, I contacted corporate GM on this issue, and they also stated this was the first they had heard of this issue. After 15 minutes of extracting from me every detail of what exactly was going on with this issue, they said I would have to take it to my dealer to get fixed. I said I already tried that and they did not fix it. GMC said there was nothing they could unless the vehicle gets recalled. Clearly, they are not standing behind this vehicle. Based on all the posts I have read in this forum, I am operating under the assumption that the dealer will be unable to fix this issue. I have forced myself to become familiar with my state's (WI) lemon laws, as I think this will be the most likely outcome of this nightmare. I have one question to everyone who has been able to get their dealer to buy back their vehicle. Could you provide a quick summary as to how you did this? I'm picturing attempting this and the dealer throwing out every excuse in the book why they can't buy the vehicle back and then I'm stuck, as neither the dealer nor GMC stand behind the vehicle. Thus, if anyone is willing to comment on exactly what basis they used (lemon laws, threat of lawsuit, etc.) to get their dealer to buy their Yukon back, I (and and I'm sure many others) would greatly appreciate it.