Boat trailer hitting car rear bumper protection.

My last vehicle I had roughly one occasion per year of the boat trailer hitting my cars plastic bumper.
Whether it was from the trailer aiming down hill a little or no one to help guide me to the right spot, it doesn't matter any more this works with out fail.
This I fixed by making what is in the pics that follow.
There maybe something like this out there, I don’t know, but I sit it on the trailer, back up till I hit it and then forward one inch and  is where the trailer is at the right distance to swing across onto the ball or just let it down there on the tow ball, with out fail, it works!
Take it off put in the car till next time and its all good.
Oh and it should be on when detaching the trailer so it doesn't move forward during and scratch the rear of your car.
Three bits of decking off cuts sanded off at the ends for no corners, shaped to suit the trailer end but still allowing to pivot and a section of nice over sized section of carpet attached to the face that the car bumps into and no worries.
I love my trailer buffer, no more scratches.