Basically you design a car from scratch (looks like some interesting engineering options and graphics) and then control the R&D, Production & marketing etc to grow the company.
Designing the car is the easy bit. Maybe not for me, but there are lots of designs and designers out there.
Making it a profitable proposition is way more difficult and a feet that not too many companies have managed. Even Tesla who have shown American can do spirit, are yet to make any money
I think what the world needs now is simple, low tech, low cost, low impact, long life, easy maintenance. Not more and more tech, more power, more rubber, more glitz, more marketing, more depreciation.