After about a year of owning two budget cameras, I would be looking for these requirements.
Long lasting battery in temperatures from -10C to 55C at a video resolution that can read licence plates.
Spare batteries and a separate battery charger. Check if you can buy more spare batteries too.
Date and timestamp remain as you change batteries.
The following don't exist yet but you might as well ask in case there are good solutions.
Good internal microphone that can pick up a conversation 10ft away while in its waterproof case.
Audio recording that stays in synch with the video recording.
Waterproof case that gives you access to the micro usb ports if you want to use an external microphone.