The coolest American supercar you've never heard of: the Scorpion_
This is the Ronn Scorpion, made by Ronn Motor Group (based in Scottsdale, Arizona) and it is a hydrogen fuel injection (HFI) hybrid which combines a HFI system which produces hydrogen through electrolysis of water using the power generated by the car's electrical system with a Honda VTEC engine.
Basically, the hydrogen is added to the usual air and fuel mix resulting in better performance or fewer emissions.
The VTEC it employs is a 3.5-litre V6 with 450 HP. The car reaches a top speed of 200 mph and accelerates from 0-60 in 3,5 seconds, which is only 0.2 seconds slower than a Koenigsegg CCX. All of this happens averaging 40 mpg.
One interesting thing about this car is the way the body is built. The Scorpion has a stainless steel frame and the body is made of carbon fibre. The original body prototype (built in California), was made directly from CAD rendering without using the traditional clay model.
It was first introduced at the Top Marques Monaco in 2009 and the price tag was around $150,000