I believe people buy these cars for 3 main reasons;
1. the name
2. performance modifications they do not have to do
3. everything is still warrantied by the dealer
The owners can still mode the car with smaller pulleys, new tune, delete plates, etc...
Also, the value of the car will be higher for insurance purpouses, for example:
you buy a Roush for $40k and in two years you total the car, the book value is $35k and that what insurance pays you.
You buy a loaded GT for $30K and invest another $10K to get all the performance goodies and then some like the Roush. Two years later, you total the car and the book value is now $22K and thats what insurance pays you. Your assed out on all the performance parts you and labor you put in, insurance wont compensate you for it and may even drop coverage if they find out you modified the brakes, exhuast and such.
Also, buying a Roush or factory aftermarket branded car holds the same quality of consistancy as the factory, if youv modded your car you know that it doesnt always come out perfect and regardless of where the work gets done, its not always great.
That said, i have a GT with a bunch of hook up parts that can kick a Roush' Ass :hihi: