Things it took awhile to notice
When the guys are trying to get out of the factory with the girder at the beginning, I've always wondered why Gaz has Nathan try to pull the girder over when Gaz and Dave are still on the car. After maybe 15 viewings over the years I finally noticed tonight that they had a second girder on the car that Dave and Gaz were going to use to come across. It falls into the water when Gaz makes the car bounce and Dave grabs him.
Damn, I wonder what else I've missed.
What did it take you several viewings to notice?