By explaining multiple times, in a slow manner of speech, that I am a high school junior, am lucky to even have a 6, and while I have 2k worth of mods on there, it still isn't close to what a GT would have cost. My parents were willing to pay $15k on a car for me. I had to pay $8000 of the car originally, I couldn't have put up another 10 for the GT. And, by the time I'm done modding the car, it'll still be less expensive than a stock GT, and look the way I want it to.
Besides, even if I had the money, the ford dealership near us wouldn't have sold me a GT. Not because of availability issues, but because the saleswoman I bought the car from was firmly against giving a 300hp car to a 16 year old. I can respect that. Even after a year driving this car, I still make careless errors. I'm a better driver than most of my peers, and I'd be scared if they were running around in cars that fast.
Besides, since I am around highschoolers, I can usually just point out, "It's better than the POS you drive."