i would check the holes where the water sprays. IF u use washerfluid it tends to gunk up and cause no pressure when spraying.

 

does Audi prescribe THEIR fluid only? I would not be surprised, I'll have to ck the manual. the Germans are very persnickety! Just another way they make it expensive and difficult to own one....

 

open the hood next to fluid reservoir is the pump pulled out very slowly you see a rubber washer you need to take i out take it home washed whit hot water check if it`s not broken then put water in a reservoir to check that should resolve trouble then pull out the pump again drain system and fill up whit windshield wiper liquid trouble solved iui juts did on my 1999 audi a6