Corrected entry: Danny Devito was going after the $5 million for the stolen fuel injection system. At the end, when he and Arnold are reminiscing, he talks about it as $4 million dollars.
Corrected entry: The two men (who left the car for Webster) told Webster the "parking attendant" liked the car. However, there are many different parking attendants with different shifts and exits in a big place like LAX. How did Webster instantly pinpoint the right one?
Correction: Webster knows when and where the car was dropped off. It's a good bet that attendant works that lot regularly. Even if he doesn't it wouldn't be hard at all to ask another attendant to tell you who was working that lot on a particular day. The fact that Webster eventually finds the right person doesn't mean that he "instantly" found the right person. We just aren't shown every step he takes because that wouldn't be interesting.
Corrected entry: Vincent named his calico cat Julius, which is a masculine name. Barring a rare genetic abnormality (approximately 1 in 3,000), calico cats are always female.
Correction: According to the submitter's own words, male calico cats do exist, though rare. So there is no mistake.
Corrected entry: In the scene where Arnold runs into the house for a shower and Danny DeVito jumps into the car, Marne goes into the house with some cookies, and Arnold has already showered and almost dried off, quite a quick rinse really..
Correction: A quick shower is not a mistake. Julius (Schwarzenegger) would be used to bathing quickly, considering he grew up on a desert island where there was little time or need for taking long showers or baths.
Correction: He only turned in 4 million, keeping 1 million for himself.