Let's say you're a multi millionaire and have loads of money to blow, is there a market for a custom car/engine? I always loved the idea of making a custom car but rebadge it as if it were a production car. Like if I had lots of money, I would love to make an inline 5 evo 6-like car but brand new and to my liking specs, could you commission a group of designers/engineer and CNC machine a brand new engine block and chassis? I imagine it's way easier to take an existing chassis and modify it to your needs and as for the engine I imagine taking an inline 6 and chopping a cylinder is easier?

What would be the correct way to approach it? Would it even be road legal?