I was lucky enough to have TVR Grantura Mk2 #300.
My personal favorite: http://www.dastank.com/Schwimmwagen-VW
We have them doing tours in Philadelphia and other coastal cities.
One would think the intake would be at the end of a vertical pipe higher than the vehicle itself and would have splash guards.
Looks like it might provide a little fun for the Top Gear guys.
The problem is that inventions like this don’t capture the public eye. An off-road, land and water vehicle will only be a novelty because it is never seen to be doing anything important or captivating. No one is there to watch a vehicle designed to take you places that no one is otherwise able to go.
If you want to sell something like this, you need to seek the grand gestures. Like Parsons “Turbinia,” for example.
Pointless unless their is a military need of it. Otherwise it is just a neat toy for hundred or two people to play with until they tire of it. Now as a military vehicle, who knows?