It would depend which engine he was going for, the DD's are always going to be caked in carbon deposits due to the direct injection alone, not to mention the EGR gasses. Very hard to tell engine condition by plenum cleanliness as it may have been cleaned out recently.
You need to get the car onto a hoist and check for rust in the chassis, listen to the engine for rattles, and check the interior for wear. If the interior isn't brand spanking new there is no way that V35 only has 69,000k's on it.
Once you buy, change all the fluids asap.