That's a good point.
I have been building kit cars since the 1980's. In that time there has been some good 4 seaters on offer but none were successful.
There was the Rickman Metisse
https://youtu.be/QjDLxN1_VrE
Chad super sport ss4
https://www.google.co.uk/search?q=ch...bqfaeEV5cJM%3A
The Ginetta g26 g28 g30 g31 had reasonable following.
And the quantum coupe / saloon sold in good quantities
So while there maybe a market - is it small and fussy?