I want to nip this in the bud before anyone thinks they can do this on their car.
In the Feb.,2013 WIRED Magazine is an article about Paul Larsen's Vestas 'SailRocket' world speed record sailboat.
Paul set a record for the 500-meter average velocity of 65.45-knots (75-mph) at Walvis Bay,Namibia,Africa this year.
The keel of the boat was the focus of the article,which is a wedge,pointed-end into the water,which at around 50-knots will form a phantom tail of air of which the surrounding water cannot cavitate,which is credited for much of the speed.
While MetroMPG and other 'yachtsmen' will find interest in this boat,the keel technology isn't something which will help us,as to an inability to cavitate something already in a vapor state.
Larsen's boat is a major advance.Check it out.