... a kit car built in larger quantities than any other kit car before.
This could, in my opinion, potentially be achieved if one designed a product upon which other kit car manufacturers build upon. I imagine a rolling chassis without front, rear or body components. A well-performing, rolling chassis that can be used by enthusiasts, replica manufacturers or designers to create any external body shapes by adding custom front and rear sub-frames, roll-over cages and body components.
The rolling chassis would have a fixed wheelbase, a fixed width, suspension and chassis layout, but be able to accept a variety of engines and gearboxes. The chassis would feature a large number of mounting points for the front and rear subframes, seats, roll-over bars, etc.
Customers could purchase that rolling chassis by itself or in combination with a second kit that features all the body parts to turn it into a Countach, a GT40, a GT, a SLC, a GTA or any other external body shape.
The chassis should have the size to replicate a modern sports car for the road (not as tiny as the GT40s). It must be priced so that people in their early careers can get into the kit car game.
I would focus all my efforts on designing this chassis for great performance and easy manufacture to allow for large production runs, potentially with suppliers in Asia, to offer them at an unbeatable price. A platform that designers throughout the world then use to create their Zonda, Apollo, Carrera GT, etc...