Every time my car went in for a service it came back with that grommet missing, there must me a load of them on the workshop floor.
The part number is 07C103226B @ £2.98
The other three black ones are different and the part number for them is like the one from pburv above. 06J103226A
Looks like your assumption is right, according to the ETKA parts database the unit fitted to you car is for vehicles fitted with Climatronic .
What year is the car? For manual air conditioning the part number is 8V0820047C for cars up to 07/10/13 and 8V0820047D for cars after that.
You can sign up for ERWIN AUDI for an hour, about £6, then just download everything related to your car for future reference.
You can also enter your VIN and it will give a complete breakdown of options and when the production date was.
I just bought a 2017 S5 so I thought I would check.
It looks like I have the latest version "B", which according to ETKA was only available from 01/03/21.
Maybe the previous owner had replaced it already or do they all just fail.
I have just gone from a 2016 FL S3 3 door to a 2017 S5 Coupe and love it.
As said above it is such a nice place to sit, more room than the S3 and it still gets me when I look out the passenger door mirror and it seems far away.
I miss the Hatchback for lugging stuff about, the boot in the S5 is...
I had mine disabled on the S3 via VCDS , no issues but looks like no way on the S5.
Like other people have found with miles on the car and heat and dirt over time mine were really difficult to remove.
When I had mine disconnected it threw up some error codes, in VCDS, relating to the rear...
After picking up the S5 a few weeks back, 25K on the clock, I thought I would check the air filter housing as some had reported debris in there.
I'm not sure if an animal had been living there but lots of feathers and leaves !!