I think he means hardwired as opposed to plug in. Mine is hardwired to the mirror and is only on when the vehicle is powered on.
It hasn't drained my battery. with my dashcam, I have the option of unmounting off of the power/ gps base if I am really worried about battery drain. No problems so far.
Did you guy's do the install by yourself or take it to a audio/video specialist for the install? I was looking @ the Blackvue DRW650 2 channel system, for front and back or DOD-TECH LS430W or LS460W they are about $230 on Ebay.. How long to leave it on before it would kill the battery. My work parking garage is full of Asshair's who lobe to ding and go.. I wanted to leave the cam's on for a few hours or instant come on if the car is bumped. Is that possible.