Don't bother with this or any cheap Chinese dashcams. Stick with the better quality and bigger name Korean-made dashcams (e.g. Blackvue, Thinkware, Viofio...) instead. You can research and buy one of these at
Our Dash Cam Collection. Most run in the $250-350, depending upon make/model, but offer much better video quality & use better components (Sony CMOS sensors) providing better day/night vision and all come with some level & combination of parking mode (e.g. time lapse, Shock detection, auto sutdown for battery protection..)
At $285-290 (Amazon -> AP! or AP2) this unit is definitely not worth the price because of the lesser video quality and no park protection whatsoever. The thing this has going for it is the plug-n-play form factor into the existing Model X mirror mount. But removing that mount you will find a constant 12V power wire underneath you can tap into and your done, after mounting one of these previously mentioned cameras to the window just below the mirror mount. And most are much smaller in size and hang down less then this one.