I tried the mustang knock off route back in 04 you need a 15+ mm spacer to clear coilovers and +5 to clear Z brakes.
however the 17x8 oem cobra R rims. fit like glove.

I sadly wasted 2k shopping for rims from 2003-2005 ASA=fail, mustang knock off 17x9 =fail 5zigen bandwagons= pass and gave in to dark side. oct 2005