2016 AUDI A3 Visibilitywiper Problems

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.

Rearview backup camera is intermittently inoperative. Cannot use camera to see what is behind the car. Dealer inspected, duplicated and confirmed problem. Dealer at first ignored. Once out of warranty, dealer duplicated problem. It is a known problem. Manufacturer issued Technical Service Bulletin: 91 16 87 2045730/1 November 7, 2016.