Disclaimer: I'm not a professional or even amateur engineer, so this is all speculation - please correct me where appropriate.
Now, I was actually thinking about something along these lines, but maybe a little bit more radical, based on the question: why can motorcycles with tiny contact patches generate such relatively high cornering loads when compared to cars with no aerodynamics?
I think that it really has to do with weight distribution; i.e., the weight on bikes when they are leaned effectively moves low and inside, pushing the contact patch, which is outside, pretty optimally. For a similar reason, I believe, the weirdo 911 weight distribution actually enables marginally superior braking performance when compared to cars where the engine is somewhere else (the 911 can use more of its rear brakes, I believe, as there is a heavy weight sitting right on top of the rear axle so it's not unloaded as much under braking).
Anyway, back to my point - consider a 4 wheel vehicle (bear with me) and a central pod similar to the 3-wheel abomination from that website that effectively moves the weight over the inside wheels via either a lean or shift corresponding with the acceleration of the turn. This would effectively move the weight over the inside 2 wheels and provide incremental usage of their grip. The tires could either lean or not - I haven't thought through the engineering.
The upshot is that the physics suggest that the weight of a vehicle needs to be in different places to optimize different characteristics: far back for braking, forward for accleration, and centered, low and inside for cornering.
Anyway, kind of a random post and probably too long, but it's an interesting idea.
That guy's trike I don't like because it's not radical enough.
cdg