On a 3 hour journey on Saturday the aircon on my Superb started off as usual blasting out nice cold air, then we noticed after around 2 hours the fan was running really slow despite what setting we tried and it was only blowing out slightly cold air, we had a break for around 90 minutes and when we got going the aircon was back to normal blasting out cold air, ever since its been fine and working how I'd expect, Does the aircon go in to a safe mode if it's being over used? What could have caused