I've only looked at their transmission kits, but apparently they break cars as well.
They seem to have a few from the UK currently.
The C5 RS6 avant appears to be a light to medium hit on the driver's side, and the seats are there, and it looks like a good candidate to either rebuild or grab parts from.
Just thought I would put it up here to see if it helps anyone else!

Link:

https://advancedautomotion.com/shop/...roducts_id/335