To start out, I have always owned Ford truck. I saw this GMC and really liked it so I went out of my comfort zone and bought....Boy did I screw up!!!!! 4 months ago I bought a used 2019 sierra with 50k miles on it. The truck looks great and runs great. The problem is that after driving it two days i noticed a large puddle of oil in my driveway. It wasnt there after the first night. I climbed under the truck and looked to see where it may be coming from. It looked like the dealership may not have tightened the oil drain plug correctly. From what I could tell the oil hadnt been leaking long. If the dealership was able to clean a long lasting oil leak, the guy that did it needs a raise!!! I took the truck back as it was still under warranty. 4 months later I still do not have my truck back. GMC is claiming it is because of parts. They say the alignment pins for the trans were bad and that caused the rear main seal to leak. I have contacted GMC customer service all the way to the top as far as I can tell (who knows who you are really taking to when you contact corporate). I just find it hard to believe that not one set of alignment pins are available when they are still building trucks. I feel like I am getting the run around here. Im at the point that when I get it back I am taking it straight to the Ford dealer and getting rid of it. Has anyone else experienced anything like this. If so what was the outcome? What might be my next steps to get something done with GMC? The pictures are of the truck and the oil leak from underneath the truck.