I don't have any pic going back that far. My prior vehicle was a Suburban, I had a hitch cargo carrier basically like this one:
Underneath the plywood was the standard steel cargo hitch carrier. The plywood was covered with boat carpet to be water proof. This worked for a while as it was 1/2 the distance to "load-up". As his Cancer got worse, I made a second deck pc. I attached it with 4" door hinges at the side so the 2nd deck would butterfly fold down on the side to create a ramp. Then fold on top of the base for driving.
My Dog was about 95#s. This was strong enough to holds him, Gayle didn't have to struggle with a heavy clumsy ramp and it didn't take up a lot of room.
I've seen a few people with these folding steps:
Mostly they had Mastiff breed dogs and they were younger. So, keep your dogs mobility in mind with this type.