Moisture problem

I own a petrol Volkswagen Polo and I have a problem. A layer of moisture forms on my windshield every time I switch on the A/C. Is there anything I can do to prevent the moisture from forming so? 

Athish, via email

AAA: This seems to be a common issue in petrol Polos and the root cause, most likley, is poor engine vent design and lack of heat insulation under the bonnet. You'll have noticed that the windshield always fogs from the outside instead of from within the passenger cabin. Unfortunately, there is not much you can do. One option is to try sourcing the insulation shield (which is not provided in Petrol Polos). The simpler (and cheaper) alternative is to mix SONAX clear-view 1:1000 concentrate in your windshield wiper fluid. Although it wont eradicate the issue, the visibility will improve considerably.