My guess is that the part numbers are
8K0823721H for the left seal and
8K0823722H for the right seal.
All VAG (which includes Audi) parts have a 9 character (plus 1 char version identifier) part number, so if you remove the part, you will be able to confirm exactly what the part number is.
With the part number, you can go to
oemepc.com/audi and put the part number in. That will show you all vehicles where the part was used and often link to an exploded part diagram with the part in it.
I found the likely numbers by browsing the Body section for the year of your S4 and finding this page