A pretty common finding, for sure. Where I work, we have weekly boardwalks where all the directors walk the buildings and view the metrics boards (updated every morning). The late CARs and PARs are clearly posted, with the process owner's as well as his/her manager's names. In addition, every time a CAR or PAR goes late, our system sends them both an automated email which repeats every week until the action item is responded to and approved. Each is numbered - "this is your 2nd reminder", "this is your 3rd reminder" ..... etc.
No one can say they didn't know. The rest is up to the registrar - if it's not addressed in a timely fashion, they get dinged.