I have a 03 mustang with the cobra r bumper/lip, and I was talking to my friend the other day and he said the mach 1 delete grill bottom lip would not fit. I could just take out the stock grill and buy the pony piece separately, but I'd much rather have the bottom lip that comes with the kit. Can anyone give me a definite answer for this please?

 

I can't say for sure because I am not sure if the opening is different for the grill there. It might be like the 99/01 Cobra where its already raised in that spot. In which case you can just paint that black and add the floating pony grill piece.

 

Depending on who made your bumper setup it should already have the grill delete built into it like the man said. Post a pic of your front end and we'll be able to give more useful advice.