CPC felt the 17-inch Styled Steel came out so well for '65-'73 and '79-'04 Mustangs that the next logical step was to offer the design for the '05-'07 model. That meant going big-make that huge-to a 20-inch version. In reality, they don't look that large on a new Mustang. The 20s on an '05-'07 are about as proportional as 18s on a '94-'04, so the current-model sizes are ideal. They include 20x9s for the front and 20x10s for the rear. You could also run 20x9s all around. The fenderwells on new Mustangs are so big that you have some latitude on tire sizes, but be careful. Consult with Autoworks, as well as other resources, when figuring out tire sizes. You could also take a page from the current Saleen S281 that comes with 20x9-inch wheels in front and 20x10s in back. Those cars ride on 275/35R20s in front and 275/40R20s in back. The 20s also accept the same red or blue wheel centers as the 17s.