I am assuming that an 18" wheel has more diameter that a 16". So what do you guys with 17"-18" wheel use for a spare if you get a flat in the rear? If you have one tire larger than the other you will burn your limited slip up because it would always be slipping due to the difference in wheel speed. Also would the ABS freak out with 2 different wheel speeds? I guess calling a tow truck is the answer. How do you recalibrate you speedo? So many question so little time. Thanks guys.