My GT (reserved for drag strip only) 10.1
Cobra R 11.1 (all mods but supercharger and nitrous)
But I think the best sounding is my 05 Mustang GT. Get the racing exhaust and go to the dragstrip. When you're sitting at the line before the race it sounds like it has a huge cam:rockon:
I kinda like the lightning and the shelby series 1. This is from the view where you see the whole car. The lightning had stock exhaust and the shelby had stage 3.