i turn 16 in 4 months too, and also want a vette, and have been researching them for like a year now, and it is gona be a huge money pit, espically a C3 that needs an interrior.
I didnt see the pic of it, but 6000 for a car with no insides and a supposed rebuilt engine seems like a ripoff to me. keep searching for em, find one that is in great condition, and buy that one.
when buying a used car, think about why it is being sold in the first place. the best kind to buy are ones from people that need to sell them fast to get cash for somthing, such as paying the bills on time or somthing. when they need the cash, they are at low prices, and useally run good, and if they REALLY need the money fast, then u could haggle them down even lower.
also dont forget about polish and other stuff too. If the car dosent have a real good paint job, wash it, clay bar it, and wax it. there are also stuff for the interrior, stuff that restores the black color to the seats and stuff. using that stuff is a great way to make your car look better.
And if you want to keep the car in good shape, then you will need a garage. I dont have one, but they sell these tent like garages that work just as well to keep the elements and animals away.
And you will need a beater if you want to drive on rainy or snowy days and still keep the vette good. (or you can always borrow your parents car if they will let ya, thats what im hopein to do
)
Well good luck dude