A rearview mirror integrated dash cam is a great choice for a vehicle where a double din receiver isn't an option. Not only is it a virtually universal solution, but the screen itself is very discreet compared to external flip up monitors or other windshield mounted displays. Lately, many companies have begun to offer combo systems that have an externally mounted back up camera, rearview mirror display, PLUS a front facing camera for recording purposes!
This sort of system kills two birds with one stone as it protects you in the event of an accident and assists you when parking. Professional installation is always recommended as running the exterior camera and reverse trigger for the screen can be tricky. It's also important to note that the video recording capabilities on these dash cams is typically not as good as even our most basic 1CH dash cams, such as the Thinkware FA10. In terms of video quality and functions these hybrid systems are typically a little limited.
That being said, as a back up camera these systems are great. In terms of video quality they offer a standard VGA resolution which is what most double din receivers and aftermarket backup camera setups offer. Overall these systems are a great value as they cost more or less the same as a normal backup cam + screen and offer the same parking assistance function while adding a basic DVR function.