Mercedes G63 AMG is definitely one of the most tuned cars in the world. The most recent customization package comes from IMSA, a German company based at Brueggen on the Lower Rhine.
They used parts in ultra light carbon fiber. In total, the body kit contains 16 parts that replace the original front bumper, left and right air inlets, both side front lips, clear cut wing enlargements, plated footboards and the rear bumper. The IMSA exhaust end bezels set the final highlight.
On the options list, IMSA includes the front grille, straps for front and rear bumper, mirror coverings, air inlets, A-pillar with front roof edge, C-pillar air outlets and, finally, the entire bonnet.
In order to “fill” the wheel wells in an appropriate way, there have been mounted light forged rims in 11×22 inches with tires in 305/40R22 all around. 
The 5.5 liters V8 BiTurbo AMG engine has been retrofitted and now delivers 730 HP and 1,035 Nm of maximal torque.