A car is a thing that takes you from A to B and you're not talking about it, until it breaks.
If Hans and the other guy had discussed a CHANGE of plans in that scene in die hard, no one would have taken offense.
That's the trick - things have to go wrong or break, so characters have a legitimate reason to talk about the thing or plan.
The extreme example: that's why films about society tend to be dystopian or tragic.
It's easier to create a story that deals with the functioning of society when it is, at least in parts, broken, and needs fixing.
Can the plan go wrong for the gangsters, somehow? Maybe when we meet the victim and the gang, they make jokes about how the guy escaped, back then, and how in the future they might just as well use an innocent person as victim, because there won't be anything to report anyway.
Or the victim doesn't get his money from the gang, and he tells them they have to use a civilian next time, but then they'll get reported to the police - a risk they'd have to live with if they don't pay the people willing to play the vicytim for them
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I can read facial expressions. I did the test.