if you want a production vehicle with locking differentials... the head of the class honors belongs to Mercedes-Benz.

The Galendewagon or G-Class in america... has not 1, not 2, but all 3 locking diffs and controls in the car via rockerswitches to engage and dissengage them... this is the one option I'd have liked to have in my TT which I just ordered

I didn't order the Adv Offroad Tech Pack because I spent a lot of money on repainting my Jeep Grand Cherokee 5.9 from my offroading escapades and dont intend to follow that suit with a 100+K Porsche Truck.... but thats just me.

Alan