I am one of those nightclub street racing guys that flies down the highway really late at night with a bunch of other nitwits trying to boost the ego and see who has the fastest car.
I have owned several kinds of cars, newer and older, with the intent of street-racing. The stretch of highway we run is typically about 6 miles long with all kinds of nice wide turns. We're lucky nothing has ever happened and the only precaution we take is to go late when there's no traffic at all.
The reality of it is, the mustang is really not a race car. GT or not, you're topped off at 120mph which isn't even a true 120mph and it's extremely expensive to buy additional parts to replace your stock. The car looks good and that's about it. It's not really worth the high price since I'm quite sure you're more or less paying for the Ford union rather than the car at the dealer. There are many 4cyl. STOCK cars out there than can drive circles around a Mustang GT. View this video for example
it's one of many.
If you want performance and speed, you're probably going to want a foreign car. Even Hyndais nowadays are quite fast and less than 1/2 the price of a Mustang.
My bottom line is, Mustangs are highly overrated. Decent car when weather conditions permit, but the performance and the classic "American muscle" just isn't there any more.