Ahh, hard cases, eh? Park by braille if no assist available? Give them a ball to aim at and a parking aid on the floor to help stop their forward motion and secure then at the desired standoff distance... the best of both.
My wife parks unaided but the Prius is dwarfed by her space in the garage. I have been thinking of setting up something to cut down on the variability of her parking. I think a ball to aim at and a parking aid on the floor to act as a positive distance gauge/arresting gear will do fine. In fact, I think I will go do it RIGHT NOW!!!
Ok, I'm done, it is built & tested by me and tested & approved by wife.. She loves it! It is a chunk of pipe insulation wrapped in a piece of red plastic (free flag from Lowe's) dangled so that she aims the center of the electronic dash instruments at it and drives till the tire is captured by the thingy on the floor.
It went fast and easy but I did ruin one chunk of scrap when I cut a compound miter BACKWARDS on one piece of scrap and had to make another one. That and I am still a little gun shy after the thumb vs saw encounter 9 days ago.
Pat