I just bought a 2007 GXP (Mean) automatic, with a little under 5,000 miles on it. The car still smells new. I've been reading the forum for a while now before I made the purchase so I did inspect the diff for leaks. I did not see any and I've checked with GM and they say that there are no open tickets on the vehicle and that the recall was performed (07204). I am hearing the noise that so many have talked about at low speeds during parking maneuvers. It's a rubbing or slight knocking noise. What should be my first course of action to protect my new investment? Should I get the fluid changed and see how that works? I have a 30 day warranty from the dealer (Carmax) Also what sort of maintenance should I perform considering that the car has sat idle for most of it's life? Thanks in advance for your help.