My 10p worth........The moulds I made for the Haynes were made in Cornwall with the help of a diamond geezer who hates kit cars but loves Mini's.
The plug was made on a Haynes chassis that I made, we used wood, foam whatever we could find then gallons and gallons of filler to create the shape. It was then divided up into Scuttle..bonnet...nosecone to ensure they 3 parts mated up.
Same for the back panel and sides.
The rear wings were made a similar way but the front cycle wings were made about 7 years ago for another firm, i just altered it a bit but both shapes I created using body filler on a tyre.........and hours and hours of sanding and sore fingers.....the whole lot was then painted then moulded

I didn't copy because there is way too much of that crap going on within the kit car Industry, i prefer to make my own shapes and leave the copying to those who can't do it themselves..I can think of a few who have and are still doing it.....