If you look at the Jetta that Chris drives, you will notice that the amount of damage to the bug-deflector on the front of his car changes almost every time we see the vehicle. It starts off with the left side of the bug deflector missing, then both sides are missing and finally it goes back to just the left side missing.
Highway signs for Route 24 show the number in a sunflower, which designates it as a Kansas state route. But the Route 24 that passes through the Kansas City Metro area is a U.S. Route, and would have a different type of sign.
When Chris Pratt calls Gary to arrange where to return the money, he tells him to meet him at 6 AM, meaning that it would be earlier than 6 AM when the call was placed. However, it's already light out, even though the sun does not rise in Kansas City until after 7:35 AM at the time of year the movie takes place (Christmas).