If you haven't checked the torque on your wheel lug nuts, I recommend that you do so. At 650 miles I finally got around to performing the recommended 500 mile check on my 2010 Shelby. I found nuts under-torqued at each position; the rear wheels were the worst. The job requires a torque wrench capable of more than 100 foot-pounds, a 13/16 deep socket or a standard socket with an extension (six point recommended over the 12 point socket), and the wheel key for any wheel locks you may have. I got a 1/2'' drive wrench at Auto Zone for around $40 and the deep socket for $6.