Chris, I'd have to second your opinion, except that part about the McLaren as I've never liked the lines. If you want a Ford GT40, then make a Ford GT40. The new Ford GT sort of fails at that, but it is about the best that could be done so the car would accomidate all types and sizes of people.
I've got a feeling that if you make this car larger, taller, longer, and bigger than a GT40 it is going to look odd and most will be put off by the shape. Just my 0.02 cents though and not even worth that.