MotoIQ ran a test between a mostly stock GT with Performance Pack and a modified E92 M3. The results were very surprising as I was expecting the 450+hp M3 to get a few seconds on the Mustang. I'd still take the M3 over the GT any day. VS the Shelby GT350 is a different story
http://www.motoiq.com/MagazineArticl...ustang-GT.aspx