Finally got around to replacing my climate control panel as it bugged me that the +/- buttons were starting to resemble something else.

The RS6 climate control panel part number is: 4B0-820-043AM
When I ordered the part from a supplier I did not have the right part number in hand. I only asked for the climate control panel for a 2003 RS6, and one that had heated seats. Unfortunately I had not noticed they sent me part number '4B0-820-043AR', which looks identical but the internal electronics are not quite so.
Basically the incorrect part number would keep the climate controller in 'Econo mode' and the AC would never turn on. You could mess around with anything else otherwise. Even though upon removing my RS6 climate control panel showed me a different part number, I figured I'd try the new one just in case it was simply a newer part number. Everything looked identical otherwise.

Here is the front fascia of my stock unit:



Given my findings were not what I had expected, I figured I would try to take my own stock unit apart. Looked around my source of tools and found that I needed a Torx T6 to access the internals of the system.

There are 9 T6-sized bolts on the outer edge in the back of the unit. Removed all 9.



The face plate comes apart and attached to it is the electronic board, which is attached through a ribbon-connector to another controller.
The fascia and the board attached to it is matted with another 9 T6-sized bolts show below.



Once I was able to remove the fascia I figured I could use all default stock electronics and simply connect the new fascia. So I decided to take the other climate control panel apart as well in the same fashion. I decided to replace the little fan and sensor that is shown in the image above as the black cylinder unit at the center of the board. That is being held by 2 phillips heads bolts.



I put it all back together in the reverse order. The unit remained the stock one regarding the electronics, and only used the new fascia and fan/sensor item.
All back in the car and working as it should.

Taking the climate control panel requires 4 radio removal tools. You can get it usually online really cheap or a dealer.
Once the radio comes out you will see 2 bolts that hold the climate control panel at the section of the panel, at the corners. Once these bolts are removed, it does require a bit of force to pull the darn panel out. I recommend putting the shift lever in 'N', hand brake on, and that gives you a bit of room to play.

I think I am done for now.... that is until the Recaros come back from upholstery shop!!!