This is the same as PlastiDip, which has been gaining popularity in the States over the last couple of years, and has just started taking off in the UK and in Europe.
Personally, I can see the benefits of doing small pieces like badges or wingmirror caps, even wheels, but changing the whole colour of a car is dumb unless you do all of the shuts as well, otherwise you see the original colour when you open the door.
It's also not that much cheaper than painting a car, although the obvious benefit of it not being permanent is there.