A dentist friend of mine had an 08 something twin turbo variety, that he bought used from a dealership, they said that all the maintenance had been done to it.
It's been the biggest POS, more to do with the twin turbo, sensors and such. It was in the shop weekly trying to get the check engine light to turn off, the dealership suggested he replace the cats, the turbo's and the computer. He traded it for an 06 with the 3.6 VR6 and hasn't been happier.
Have you considered the twin-turbo V10 diesel VW toureg? it's no porsche, but rare and comfy.