Factual error: Throughout the entire scene in the police car chase, the slushy on the windscreen seems to have a host of problems. For starters the slushy is covered completely over the windscreen. Franco was hit and the slushy landed on the windscreen. Unless it was poured evenly down, it would spread out from where it hit. It could cover a good area of the screen, just not the entire screen. The next problem is the density of it. Certainly it could cover much of the screen but it's primarily ice and liquid. The substance would slide down the windshield and dry up. The fact they are driving so fast, swerving around etc., would mean the substance wouldn't likely stay stuck to the windows. Even if it had a good deal of time to stick, it would be near impossible. Finally the windshield in many shots appears to be in blotches like a painting. Again, the substance is not paint, it was spilt on and was only one substance. The substance might be more concentrated where it hit, but it would be less concentrated in other locations.
Factual error: Several times throughout the movie, Saul talks about daylight saving time and changing his grandma's clocks. Daylight saving time always happens on Sunday, but in the beginning of the movie Dale was visiting his girlfriend at school, so at the latest the movie took place on a Friday - Saturday, (Tuesday if you go by the fight scene in Red's house), definitely not a Saturday - Sunday.