Need help on this topic, My superb's temperature guage going above 90 when the AC is on and then AC cuts off when it reaches about at 110. Had recently got my AC relay changed at a skoda service center few months backfor the same problem.

Could it be your radiator problem and it might be leaking on coolant water

When the AC switches on, a second fan on the radiator is meant to kick in. if this second fan has failed then you'll have cooling issues.