Constantly dirty windscreen (inside)

[matjk]

Got myself a 2012 Elise SC , and every time I begin to drive it the windscreen inside is covered in what looks like mist, I thought at first the AC would clear it, but it did nothing ! It's not mist , it's dry and cleans off easily with a cloth but it's a royal PITA , it completely covers the whole inside windscreen and I'm clueless as to what it is? Any ideas ?