Ok, I came across this wicked post on Hi Consumption and just fell in love with the Watercar Pather Amphibious Jeep. Now I have seen a few amphibious cars in my life time, but none that can travel up to 44 mph (about 70 Km/h or ~38 knots since we are talking water speed). And with a land speed of 80 mph (~128 Km/h) this vehicle is a beast on land and sea.
The kit is available in the states in 3 different stages (as some states have higher regulations for custom-built cars and how they are licensed for road safety) with the full build priced at $135,000. Take a look at the video for some action shots of this amazing vehicle in action: