Happens on mine too. Getting some moisture absorption packs from Amazon, eBay etc can
help, just remember to take them indoors with you from time to time otherwise the moisture will just stay in the car. I just chuck them on top of the dash and they do reduce the amount condensation/ice that occurs inside at times.
Similarly, if you use a demister pad to clear the windscreen don't leave it lying in the car otherwise it's just releasing the moisture back into the air.