Is it the ea189 recall? If so my advice would be to get the car remapped to get rid of the software update they've done. If it is this recall it's because of the emissions scandal. Some engines were just a software update whereas others had a software update plus an additional bit added to the engine either in the air intake or turbo.
I worked at Volkswagen service department when these recalls were done daily. I certainly wouldn't recommend this recall on any VAG car.
Here's a long thread about it:
Hello James,
Thanks for being in touch with the forum.
I’m not sure about the smell syndrome, but in terms of the pitfalls of not steering well clear of Audi’s recalls, the experiences are listed and complained about on here, and cover multiple pages.
Well worth a forum search and read.
Kind regards,
Gareth.