After about 10,000 miles I noticed that when I pulled out of my garage and idled in the driveway (usually waiting for the wife) that the whole truck would have a noticeable shake to it. This happend on several occasions but the dealer couldnt duplicate it. Finally at 20,000 miles I took it in again and they found that the throttle body was dirty and the flap wasnt opening all the way. They simply cleaned it and now it idles just fine.