I'm not new to Porsches, but I'm looking at a Cayenne Turbo at the moment and a bit concerned about issues I've heard about such as the gearbox etc.
I'm a true petrol head, I have owned a few 911's and a couple of Ferrari's and the useual day to day stuff.
From what I know the issue your talking about with the Porsche Cayenne gearboxes do happen more than it should in the earlier Cayenne's. As long as you sick with the newer Cayenne's you should be fine.
I believe the main problem was that gears were slipping.