NHTSA Complaint #11666478 — 2016 AUDI A3

The rear wiper hose is consistently getting completely clogged so that no fluid comes out when the spray mechanism is engaged. The dealership has replaced it for a fee two or three times. At the last service they told us they cleaned it and did not charge a fee. However, within two months it was clogged again. I have noticed that the issue is more likely to occur after (intentionally or accidentally) using the rear window defroster. I am therefore wondering whether the hose is made of a plastic that is too soft, causing it to change shape as a response to the defroster heat.