I have had both and a wireless setup. The license plate setup sucked. Very limited on what you can see. Wireless required more wires than the wired ubit, and constantly frashed on and off. It was much worse than any camera I have had.
I finely went to a camera that had a 5-wire cable (about 1/4" in diameter) that went from the camera to the back window if the truck. It coupled to a second cable that went inside the truck to the monitor. This coupling allows me to disconnect the cable between the truck and TC. The camera is the hard of the system. You can choose distance, wide angle, infrared, and combination of each. I found you must mount the camera below the TC clearance light, or the light will drastically interfere with the infrared. I can see all of my Samurai and most of the tow bar, and also see about 1/4 mile (or more) behind me in total darkness.
Wayne