Fyi, we also had a vibration (@48k) our dealer tested it and said it was a torque converter problem, recommended transmission flush(@54k). This has seemed to fix but now after 27k more miles we are afraid it is returning. BTW, our giubo was cracking we just had to pay a $100 deductible to have it replaced...we noticed the cracks at 48k but pushed replacement to 81k.