         // If identifier is "licensePlateNumberChanged", then we can obtain the new license plate number from the VC
         if segue.identifier == "licensePlateNumberChanged", let licenseVC = segue.source as? CarLicenseViewController {
             self.licensePlateNumber = licenseVC.licensePlateNumber
+            self.delegate?.detailViewController(self, didChangeLicensePlateNumber: licenseVC.licensePlateNumber)
         }
     }
     


protocol DetailViewControllerDelegate {
    func detailViewController(_ controller: DetailViewController, didSelectZone zone: Zone?)
}

    
    var delegate: DetailViewControllerDelegate? = nil
    
    // Default license plate number to use
    var licensePlateNumber: String? = nil {
        didSet {
            self.updateParkButton()
