So finally I got some alone time with my A2:
1. Replaced the dog bone (fitted Lemforder 36324 01 - it is 100% identical to the original one) - I was hoping very very much that this will solve the annoying rattle - but it did not
I have "taken good care" of all bolts I removed.
So it is 3:0 for the rattle - oil pump chain replaced, aux belt tensioner replaced, dog bone replaced - and no effect
2. Removed earth wire for the starter motor - it was corroded at chassis side (the car started well before this, but it could start better) [I hope person that designed the place for the chassis connector will have a special place in hell].
3. I have added additional earth connection for the wiper motor (this was a preventive action) - and here I am most surprised - the wiper is now moving noticeably faster ... (the grease there is vaseline).
4. I have greased wiper linkage mechanism - just to let it work better.