Height of wireless cameras advantages/disadvantages

I have a camera mounted on my trailer with the license plate bolts and have no problem seeing what's behind me while going down the road. At a stop light I might only see the tires and grill of the first car behind me but when traveling I can see enough. Having the camera up high would be better to see around a close vehicle and maybe be better to see into the passenger compartment so you could tell if the other driver is giving you the bird. I planned on rewiring my camera and mounting it higher but after using it while mounted on the bumper I see no need.

My truck camera is also on the license plate which works great for getting under the hitch and that is all its used for as I find mirrors work just fine for backing my truck up.