I just recently started messing with future and I went to coat my clear parts (to cover a small scuff which worked) But In some spots the future formed a build-up. I had tried to avoid this by suspending the parts while they dried. Which worked to because the two parts that built up were in the middle and top area. So I went to remove the future after it had dried with windex like the complete future site suggested. After application and scrubbing. I then dried with a paper towel and the parts that the future hadn't come off of were milky and cloudy like Roman is talking about. I had to soak and scrub to get the clear parts clean again.
Oh well.