Because the "normal" G Wagon is too mainstream!!! 6x6

Mercedes-Benz G63 AMG 6x6

The G63 AMG 6x6 is a six-wheel drive beast running a 5.5 liter V8 AMG engine powered with 536 HP making it the the most expensive legal offroad SUV in history.
The car has a gorgeous and luxury interior making the offroad experience a beauty beyond difficulties. The six by six monster my Mercedes-Benz was launched in 2013 with production exceeding 100 vehicles untill nowadays. 
If you have 600 thousand dollars sitting around it would be a good idea owning a beautiful monster like the 6x6 AMG.