Eight left to solve.
The response so far has been excellent but it may be necessary now to provide a few clues for the remainder.
#1 - Look at the wheels to guess what this car may be based on (and it's not Italian)
#2 - This marque shares its name with the surname of a long time British racing driver
#6 - Looks Italian but it's not
#8 - Unusual British engine although the car itself is not British
#9 - A famous marque well-known for its single seaters
#11 - Looks like a miniature Ferrari but of course, it's not one of those but it is Italian
#18 - Look at the airbox - I think this car was the only one with this shape
#20 - It's not European or South American
I'll add further clues if any are proving tricky to guess over the coming days