Bruce,
Having seen movies on the lives of Edward Weston and Ansel Adams, last time I bought a car I tried to get an all wheel drive vehicle whose roof rack would support a sheet of plywood, 8x10 camera, tripod and me. 150 # capacity seemed about top. My doctor the car sales people and I all had a good laugh. I noticed that RobertP bought a Land Rover Discovery which would do that, but I was not comfortable with their Consumer Report service ratings.
If you are not going far from the car a small cooler with a flat lid and non skid tape from a marine store can be a double purpose item. If you have lots of room a three foot step ladder is useful.
I am curious about your measurement "I'm not an unusually short person (5' 6-8")" My waist line goes out and in with diet, but I haven't found anything that makes me grow two inches taller. How do you do that?
John Powers