New G8 GT - 400 miles - TPMS fault and other things...

I don't know if this helps (and I just joined so it may be answered elsewhere) but I bought a G8 today. While test driving it, the car shakes. Not a lot but enough. Since I had heard this was an issue, I was extra sensitive to it. When I returned, I asked the dealer what was up. My salesman didn't know but he called someone else over to ask. That person said it is a common problem with the G8s and he wasn't sure why but he would check recalls and what not. Well for me, the deal was off until he came back with a printed page which said certain GM models, G8s included, had received faulty tires. The recommendation was to rotate and balance them (don't know how that helps) and that should correct problem. He said if that didn't, they'd replace the tires. So I bought the car with the intention of turning around and going back if needed. I pick it up tomorrow so I will know soon.

Check out the Genderal Discussion forum titled "Anyone having problems with Vibration on G8 Gt's" (or something very similar). Just an FYI, my G8 Gt had the tires balanced, then road force balanced, then replaced and road force balanced, and now they are goinging to try to replace the engine and transmission mounts to see if that stops the vibration. I bought my G8 on March 27th brought it in the first time on April 2nd and have been trying to get the vibration issued relsolved ever since. I beleive the vibration is caused by the AFM kicking in that's why you only feel it at constant speeds.