I still try to figure out how we got the 8 of us in the car, plus camping gear, clothes, and some food in that car, to be gone for a week or ten days. Mom was a master at packing things up. I guess it helped that Dad had been in the military, and after he was out, we moved every couple of years with job changes for him. Packed a lot of stuff in a little bit of space. (That tent was canvas and not lightweight like the nylon ones nowadays. Very bulky and heavy.)
My dad built a large plywood box that went on top of the station wagon for our luggage, gear, etc. He had these two things that clamped on the sides of the roof (similar to ski racks you see on cars these day) & the box was strapped on that way. The box was almost the width of the car roof & maybe 2/3 as long. It held a lot of stuff! I don’t know what happened to the box, but I saw the old ‘clamps’ in the pole barn the last time I was at the Old House.