I've seen these concepts & working prototypes several years back (2005-ish)..
It was mainly considered for use on army vehicles because of their inherent benefits in the military environment >


SLOWLY coming around to the consumer market (2013) >


Still not really available to the general public (2014) >





Very cool design and fantastic invention, but if you want to get your hands on a set, like these.. They're as rare as tryig to find white crocodiles in the wild.

 

They are around in the skidsteer world but the price keeps them rare. I own track machines so no need for tires but if the prices come around I'd consider them on my car