Write the new password on a piece of masking tape and stick it to the back of the DVR mount.
These devices are popular because they are cheap, feature 1080p recording, loop recording, G-sensors, and—most importantly—built-in WiFi to view footage on iOS and Android. 168 car dvr wifi password
If your DVR has a removable battery (like an action camera), remove it and read the fine print. Often the default password is printed there. Write the new password on a piece of