Ford does sell all the parts that come with the pony package seperately, but it will cost you an arm and an leg. I would recommend buying the parts yourself from seperate dealers. You can buy take off wheels from several different places, just search around. This will save you alot. You can also get the gt rear sway bar as a take off, and same goes for the gt spoiler. The pony package grill is a little more costly, I believe moss muscle sells it new. If you want to buy a used pony package grill and save some money, shoot me a pm. Doing it this way will be a lot less hassle and cheaper, and install is a breeze on all these parts. Good luck.
