Good luck matey, obviously you know an HPi is imperitive on these cars as an alarming number seem to have left the road backwards. I would also get an inspection done mviuk.co.uk are excellent ( remember it may be unrecorded so 150 squids may save you from losing significantly more ).
There was recently an RS6 on ebay that someone bought with a clean HPi then found out the car was out of kilter after a major impact and would cost in excess of £10k to fix properly, he bought the car for 12k and sold it for 4k OUCH
