It shouldn't ever be TOO dry. Although it can be moe difficult the more the clear cures, it shouldn't ever be to the point where ya can't sand and buff. Assuming you used all the right products for the temperature you were spraying in, 2 days should be plenty dry. just try a small spot with some 2000 grit and see how it rubs out. If the clear sands easy, paper doesn't drag excessively, then you should be all set to polish it up!
Scott