car cover trapping moisture
 

I bought a cheap ebay car cover during the summer, ready for when i took my car off the road over the winter, it was basically just to keep the dust off my car and a few rain drops where there are tiny holes in the asbestos roof of my garage.

The cover has been fine up untill the last few weeks where ive noticed moisure on the paintwork beneath the cover, is there anything i can do to stop this but still use the cover? would a more expensive cover stop the moisure, my garage is not the driest of places but it certainly better than it being outside.

Is the moisture that is trapped beneath the cover likely to cause any damage to the paint work, the last thing i want is my paint work damaging.

Thanks Tristan