I agree on both counts!
If the Mach is the base 351, the standard rear valance would be correct, any other optional engine would get the cut-out valance with chrome oval exhaust tips. A complete new part would be the best solution with the honeycomb panel and pop open gas cap. Lets see..wheel covers, grille, standard scoop, shaker, engine parts,door panels, seats, possibly the exhaust system, quickly adds up to quite a few parts! Don't forget about the Mustang emblems above the Mach trim on the front fenders! I guess this and the trunk Mach 1 letters will give the photoetch guys something to sell! Wouldn't a photoetch grille be something excellent for this car??
I really miss my 1:1 2003 Mach! Azure Blue, automatic ran 13.47 bone stock with just over 10k on the odometer...
If I start converting a 99 Cobra kit to a Mach, the probability of getting a 2003-2004 Mach kit goes up greatly!