Plot hole: Jimmy tells Oz to "pull out the wires" from under the dashboard to hotwire the car. Firstly, car manufacturers (including Buick) don't have the ignition wiring that is easily accessible, and secondly, assuming the car didn't have an immobiliser, at what point was the steering lock broken? Er, it wasn't.
Plot hole: Why do they need both halves of the torn dollar bill to access the bank account? All American bills have a copy of the serial number on each half, no matter which way you tear it, as long as it is in roughly equal parts (top and bottom or left and right).
Plot hole: When Jimmy calls Jill in order to get his bag back she is let in on the entire thing and gets to play her part in rescuing Oz and Cynthia. She asks Jimmy if he would have called if he hadn't grabbed the wrong bag to which the answer was no since his intention was to drive her away in order to protect her. Jimmy tells her to remember everything he has told her (which I'm assuming was for her role in the upcoming rescue) but since he tried to drive her away and they had not talked since their big fight when did Jimmy get an opportunity to tell Jill what to do in the first place?