when in reality ford offers the mustang in different "base" levels (i.e. v6, gt, gt500) so the customer can choose where their upgrade starting point will begin at. from there the owner can do the aftermarket modifications they prefer to have, wether it be for the drag strip, the track, or a comb...
i used to deliver pizza with this blaring out of my car while standing at the customers door. those were fun days..........