The creamy stuff is an oil and water emulsion. I would suggest the following checks before starting to get too worried.
1) Is there any sign of oil in the cooling system? Check the expansion tank. If so, then you may have a problem.
2) if not, check that the crankcase ventilation system is working and not clogged up. Disconnect any pipes and clean out if necessary. I'm not sure where they are on the A3. Look around the engine there should be a pipe running from the crankcase to the inlet/inlet manifold somewhere.
3) After you have done this take the car for a longish run. Long enough to allow the engine oil to get hot enough to evaporate any water present.
If after having done all this there is still a problem then you will have to further investigate how water is getting into your oil.
I have a '98 1.6 A3 and have never had this problem but I have had it in other cars especially if parked outside in winter.