Link to AudiWorld thread I found:
https://www.audiworld.com/forums/a8-...iment-2932568/
Seems in the US the parts are $5, and if you search eBay for ‘ Febi part number 10023’ you can find them for under a tenner for 2!
Although the listings don’t state they are compatible with the D3.
OP of that thread reports 2 years use without issue.