Man...if you fall asleep...you miss a lot.
If the build sheet lists :
S534A KLIMAAUTOMATIK Automatic air conditioning ... then that is the IHKA control panel. The IHKR is the manual control panel that has the 3 round dials that use bowden cables to operate the air flaps & temp control, etc.
And with an early build date...your IHKA control panel would have the REST button and not the MAX button. So, if you wanted to upgrade to the an IHKA w/MAX button...you would have to find a new or used one, then code your car so that it can run the extra programming (max cooling) feature. Your vehicle won't automatically perform the MAX function without reprogramming.
Below is an illustrated diagram of the manual IHKR control unit: