I also have been mulling this over recently, must be the weather.
I have seen these adaptors but the company in Germany dont want to reply to confirm if they fit my actual engine, 91 Coupe 2.3 7A
https://www.ebay.co.uk/itm/Audi-90-Q...53.m1438.l2649
Not sure where you lads were looking at the adaptors ?