Kit cars can be built to many different levels and driven well or not so what you saw may not of been a very good example.
To do this right it takes a great deal more time and money than kit car companies tend to portray, I was going to build the GTM for a track car but it would of cost a small fortune in time and money making major changes and then not being able to buy a frame section or body panels if some were damaged in racing so I backed out.
If I were to build the 818 coupe it would be a street/track car and end up costing at least $50k and take 1,000 or more hours and likely much more time.
It would be far more cost effective for me to just start another business and make the money there and buy something already built but I like projects
Imagine a Cayman R but more power and 800-900 lbs less weight