I've just found out the my Blackvue dashcam overwrites the oldest file eventhough it is an "Event file". Consequently you have to immidiately stop the car and backup an Event file that you want to save, if you wan't the ensure that it is not deleted. (I'm aware that it may take several hours before the Event file in question will be deleted, but there's always a risk that you forget - or are unable - to back the file up once you reach your destination.
My previous dashcam, which unfortunately stopped working, marked "Event files" as "Read only" so they would not be overwritten later. The dashcam also had a button to manually mark the current and previous file as "Read only".
While I fully understand that you won't be able to add a button as described above, just marking "Event files" as read only would solve the problem, as a light "tap" of my DR650S will mark the current file as "Event".
Considering the fact that you already recommend a manual formatting of the memorycard regulary, there's no risk that the card will be stuffed with read only files.
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