Factual error: When we see the impression from the radiator cap that shot into Ian's forehead, it says 'HOT'. Since the word 'HOT' was written correctly on the radiator cap, the word on his forehead should be backwards and read 'TOH', not 'HOT'.
Factual error: There are several mistakes relating to the Youtube video from the abstinence talk. Firstly, the user joined two minutes ago, and has 11 videos already. Secondly, his one video has over 5.2 million views, in less than two minutes. (01:17:10)
Factual error: When Ian has the gun while he's in the doughnut suit, he manages to fire it. But the fingers are so big, there is no way it could possibly fit into the trigger guard to be able to pull the trigger.
Factual error: When Ian throws the tyre iron and it goes through the cop's window, the window should at least have cracks in the glass. However it doesn't. (01:25:45)
Answer: LoJack.