No, they don't.
ETA: I will agree that Mustangs can be many different things to many different people, but from 2005 on Mustangs have been GT/Sports cars, and from 2011 on they're properly compared to M3s and 911s, not Challengers.
Still not convinced Mustangs are sports cars. How about a direct quote from Ford's brochure for the 1965 Mustang?; "You can choose from over 70 options, and design your Mustang as a hot blooded sports car....."
Im not sure what you're arguing here. I said earlier that the S550 will be a better driver's car. I might seriously consider one if I could afford it, but I cant and dont want to give up my car to make it happen either.
A 50 year old marketing brochure doesnt exactly prove your point when the whole rest of the automotive community has been using a certain lexicon for the same amount of time.
Lastly, you are being ludicrous is you want to compare a Mustang GT with high end Euro cars. I know Randy Pobst ran a stock Track Pack with an M3 and that is super impressive.
However, my car is a premium GT without track pack or brembos and it came with 235's and 18's from the factory. I will tell you that the handling was woeful until I got better and bigger tires, wheels, dampers, springs, and control arms. Ive driven new track pack/brembo cars and as good as Randy Pobst may be to coax one around a track on pace with an M3, the average guy wont be able to do it as even the track pack/brembo cars are sloppy handlers out of the box with OEM rubber.
2011 Mustang GT M6 3.31s
Matt HONEYCUTT Tune, Lethal Off-Road X, GT500 axlebacks, J&M LCAs, UPR UCA, Whiteline LCA relocation brackets, Eibach Pro-Kit Springs, Koni STR.T shocks/struts, GT500 strut mounts, SR Strut Tower Brace
Best 1/4 E/T (05/18/14 MIR - no tune, X-pipe, or UCA): 12.920 @ 109.40 mph (2.059 60ft)