Hi all. Looking at buying a 2.5 TDi. I been to look at a 1999 A4 SE on a T with 103000 miles on it. When I looked underneath the car I noticed there was oil on the plastic guard under the engine sump. I have since read that the early V6's can suffer from oil leaks. Could you please advise me what to look for & where? Also, is there anything else I should look for on this model? Many thanks John.