Like cell phones and action cams, the dash cams are continuously evolving. Go on a Chinese web site like AliExpress or BangGood and there are some 50 different models available. Decide on the features you want (front + rear cameras?, built-in display? wifi to your phone?...) Find one that uses an adhesive mount (not suction cup) and is as small & inconspicuous as possible so it's less likely to attract thieves.
If you drive a newer model Toyota, there's a "factory" dash cam with I believe cleaner wiring (plugs into the mirror connector) and a time-lapse mode to keep recording while parked.
Garmin Dash Cam 65W. I bought them for my cars and for my parents. Nice little unit. There is an optional connection you can buy/do that’ll record when the car is off.