I'm starting to get into investing, and came across a very interesting company. They claim to have a system that greatly increases both the cars power and efficiency. (the stock ticker is NHYT).
There is also a 500 HP, 32/28 MPG Silverado.
They also claim to be working with General Motors so the system includes a 5 year, 100,000 mile powertrain warranty. I don't know how much the system costs, however.
The website is
http://www.neohydrotechnology.com, it's pretty interesting, take a look.