I just came across this thread, so I'll throw my two cents in. Last year, being a complete newbie, I tried to invent all kinds of stuff. I made myself a large mirror that attached with magnets to the angled steel tube on my 5th wheel Scamp
. I hoped to be able to see the ball and the coupling from above, in the rear view mirror. The alignment of the mirror was never right. It was always different, depending on the angle of approach and how level the ground was. What worked for me well however, was the white line I painted in the bed and on the tailgate of the truck. When the coupling is above that line, I straighten the steering wheel and back up the rest of the way. I may need to step out to look if I cannot see the ball and coupling over my shoulder. That happens when there is stuff loaded on the back seat and I cannot fold the back part way. What still bugged the heck out of me was the need to lower the tailgate, back in part way, get out, raise it and finish. I realized that if the gate can be held half way up, I can save that step. Its top edge needs to be just a little lower than the ball, and it just clears the gas tanks when connected. To hold it up at about 45 degree angle, I use a piece of 1/4 inch steel rod that I bent to hook onto the tailgate "hook" and the other end is simply ell shaped and engages the tailgate latch. I stash it and close gate when done. I like being able to do the hitching by myself, without a helper judging how many inches to go and which direction. We may have a communication problem! And usually the helper is busy doing other things anyway.