She has sprung an oil leak
 

I think I have a small oil leak, although I am unable to determine the source.

In the two years I've owned the D3 i've never really needed to topup the oil, regular checks showed that the level has remained fairly constant and only once have I put in 1/2 litre.

Checked the level today prior to visiting family over christmas, and its at or just below the minimum mark on the dipstick. Engine warm and oil left to drain back into sump for about 20mins. I've now restored the level to where it should be, but needed to add quiet a bit to get back there. I've probably driven 700 miles or so since it was last checked maybe slightly more.

Looking around in the engine bay, it looks like the undertray has oil on it, on the nearside. Looking down you can see it right under the engine, and it appears to run across to the offside. Most of the oil is on the nearside, and just a few drips on the driver side. There is no sign of any oil on the block, round the rocker gaskets so it look like something low down.

Initially thought oh no, oil cooler but thats the other side and there is no loss of coolant or any signs of oil mixing with coolant.

She is due a service in the new year anyway, was going to use Audi fixed price service but not sure now given this leak and how much Audi would charge to diagnose.

Any ideas based on the above?.

Mine leaked when the numpties didn't replace the sump plug washer. Was fixed with a new plug and washer. That leaked towards the near side of the undertray. Is that something you could rule out?

I'll need to check, although the plug has not been disturbed for sometime its quiet possible I suppose. I'll monitor usage for a while to see how bad it actually is.

Well, I've covered the best part of 1,500 miles since the low oil condition and all is good so a false alarm. Oil level has remained constant despite travelling around most of the south of the UK since christmas. I've done the best part of 500 miles in the last week.
What I thought was oil on the undertray has gone, so it must have been dirty water. I live on a farm and the car is subjected to a muddy farm track everyday.