Fiberglass fabricators usually want you to pay upfront to make the mold.
It costs about the same as making the item, itself. They do this since
they don't know if there is a market for what you want built.

They also want you to pay for the product coming out of the mold.

An alternative.....
Do you think a company that already makes a "fiberglass" body
kit would be receptive to making you some parts in carbon fiber?
Do you have some minutes on your phone to find out?....and
when you call them, *don't* say it's for a street car!
Keep us posted.