Don’t worry, creators have already thought of that problem way ahead of time. While you’re mostly going to see this in built-in models, your dash cam comes with a feature that rewrites old data. If you can get three hours of recorded footage, it will start rewriting that first minute, moving forward, and so on. Either way, you’ll have X amount of previous footage to reflect on. If you need that footage ASAP, such as after getting into an accident, just pop out the SD card, put it somewhere safe, and put the alternate SD card in.