Mustangs are NOT fast, end of story.
you take your standard 4.6, throw a blower on it- what do you run? mid 12's at DANGEROUS boost levels.
take an LS1 f-body, WITHOUT TOUCHING THE MOTOR you can dip into the 11s.
yea a few hundred bucks will get an 03cobra to 500hp, but i guarantee you i can find a hundred ls1's pushing 400hp that'll drag their ass down the 1320.
Mustangs are good daily drivers, they're quick, they sound nice- but dont try to compare dollar for dollar straight line performance with an lsx based car.
I also work at carmax, been there two and a half years- and in the time i've been there weve only had 3 or 4 fbodies kicked to wholesale that werent over 100k miles.