Smaller Wheels?

Yes, 15s are too small, however, there is a place (I can't remember the name, use google) that offers a kit that puts SN-95 rotors on the rear to allow for 15" drag wheels. The front is a different story, I think they are fine assuming you use a spacer, skinnies, and longer studs.
 
Yes, 15s are too small, however, there is a place (I can't remember the name, use google) that offers a kit that puts SN-95 rotors on the rear to allow for 15" drag wheels. The front is a different story, I think they are fine assuming you use a spacer, skinnies, and longer studs.

They are featured in the current MM&FF

What about 16s, does anyone know? Thanks.

16's would fit but you would have to mimic the exact backspacing and offset of the wheels that come on the 05 up Mustangs.