Jason,
If you are still monitoring this post, please refocus your efforts. The car you drive to your prom is irrelevant. You will pull up, a few people will be outside, and see you get out of the car, and then you have to go in and have a good time. Except, if you drove a GT40, you would be thinking about the car out in the lot the whole time and not the girl on your arm. If you want to impress your friends, bring a hot date -- not a hot car. Don't make your senior prom a disappointment because you couldn't drive the car you dreamed of, make it a nice memory by having a fun night with your friends. The cars will come if that's what you still want later in life.
Dave
PS I would gladly buy you a GT40 if you could figure out how to make me 18 again