It's not in the same league, but a friend of my dad's used to build dirt track super sedan speedway cars: http://www.speedwaysedans.com/index.php/super-sedans

It's not in the same league, but a friend of my dad's used to build dirt track super sedan speedway cars: http://www.speedwaysedans.com/index.php/super-sedans http://www.speedwaysedans.com/index.php/super-sedans It basically consisted of fabricating a frame and some body panels and then bolting bits you'd bought from elsewhere, but 90%+ of the construction/assembly work was done by a single guy (the other 10% being the paint guy across the street, and calling on people to help him line up and hold things in place while he welded). If any plans existed (I never saw any) they were probably on a scrap of wood. It's not as glamourous as a Pagani, but the cars would still cost over $100k and some of them went on to win national championships and similar. Turns out a lot can be done by one guy in a tin shed.