Update: I went to the dealership so they could check it out. First, off topic, the crunching sound I heard over bumps is normal when it's very cold outside. As for the misfire, which this time was 50 or 5 seconds worth, the tech said he couldn't replicate it and he called GM. GM is not allowing him to go ahead and switch out parts since they haven't had this problem before. The tech cleaned the injectors and inspected the plugs. He also said he was gonna look for an update in the software, but then found that the software in my car was newer than what was out. Which confused him and me, especially when he asked if I had it tuned. He said until it blows a major code and the engine light stays on, not to bring to the dealership because GM will keep giving me the run around. He said I'm covered no matter what since I've brought it in twice and it's been documented, even if OnStar's Diagnostic says to have it checked. The other thing the tech did do was, as the paper states, "Performed Relearn Crankshaft Variation"