I had the same problem. Brought some silca bags which helped a little.
I read somewere that if the inside of your windscreen is dirty then this can give the moisture something to cling to. So I brought some top of the range car glass polish and gave the windscreen a good old polish. Even though it did'nt look dirty you'll be amazed at the crap it removes. It seems to have worked , as I hav'nt had the problem since....
