The W Motors Lyken Hypersport is a $3 million with a RUF tuned Porsche flat-six engine that makes 770 horsepower. It can launch from 0-60 mph in 2.8 seconds and hit a top speed of 245 mph.
The Ariel Atom gives you about as close an experience as you can have on the road to a Formula 1 car. Thanks to the open frame design it is an experience like no other. Add this to the lack of windshield and it makes most cars from Lotus look fat.
You don't really need any.
It is a custom build.