Car/Truck Mirror Monitor Mount

This is a monitor mount for a 4 camera vehicle mounted system. All 4 cameras record constantly. I purchased this system on ebay. Here is the description line if you are interested.
9" QUAD MONITOR WITH DVR 4 x SIDE CAMERAS SAFETY SYSTEM FOR TRUCK TRAILER RV
I put it on a wheel lift wrecker I use in my business. The constant recording give me the security that what takes place is available to show police or judges later should the need arise. The cabover truck I have really doesn't need a