I bought one off Ebay, one of the no name cams recommended by someone on this site. It would not stay in the record mode, contacted the seller, never got a response.
So we got a GoPro and it works like a charm. Only issue is the GoPro battery will not last more than about 4 hours recording so you have to keep it plugged into your 12v power source.... another gizmo on the dash looking for a place to plug in :R