Instruments showed a call to
viewWillAppear:, a part of the view-opening cycle, and that gives you a place to start with the debugger. To be safe, put a breakpoint in both
ViewCarTableViewController.m. Optionally, you can practice editing breakpoints and set the ignore count to 1 since you know the first call works.
Run the app and reproduce the crash. If you did not set an ignore count, or if you have to try multiple times to reproduce the condition, continue using the keyboard shortcut Ctrl-Cmd-Y instead of the Product > Debug submenu.
The app crashes, but it does not hit one of the breakpoints. That gives you a possible clue. You need to look at what you know: