S3 or S4 seats in an Audi 80 or other sports seats?

Hello.

I would like to install the sports seats from my Audi 80 B4 into my Audi S3 or S4.
Who knows what will fit and/or what changes I need to make?
Or are there other sports seats from the Audi/VW range that would fit?

And what does the TÜV say about it?

Best regards,

Didl