105 is within acceptable range, and these engines do often run quite hot. The gauge on the cluster is conditioned to read 90 between 85 and 105 actual iirc. The only way to know for sure is with VCDS from the ECU which measures it directly.
Bizarrely, the cluster passes a guesstimated temperature reading to the climate control based on how long the engine has been running and the operating conditions, despite the fact that it knows the temperature from an actual sensor
