We're getting there. My loading plan turned out to be full of reality-induced errors. Dwight Eisenhower profoundly said, "plans are useless, planning's essential."
Anyway, have now fully loaded the expedition box and test-driven it. The car is definitely a little light forward, but shows no signs of gross misbehavior, and the box / mount seem to be steady. I have no real idea what the current load weighs, but I'm guessing 350 pounds including platform, box, and contents.
Here's what's included:
Air mattress pump
Storage bag for sleeping bag
Two boxes (24 servings) MRE (meals ready to eat), about 50 pounds worth
Tackle box 12 pound test line, updated lures and misc. tackle
Fileting knife, skinning knife
Hydraulic Jack plus handle
Heavy duty come-along
Socket and box wrenches
Cordless drill (heavy duty), power bits, drill set.
100 feet misc Rope 50 ' dacron 1/2 inch dockline
30 foot towing strap
JUMPING BATTERY & 12 VOLT CHARGER FOR IT
Frying pan / dutch oven (covered pan)
2 burner stove plus 9 ne-pound propane bottles
Propane Long match
Tripod & Monopod == mount inside box lid, along with fishing rod
There's a ton more stuff INSIDE the car, including large dog, 70 days dog food, clothes, cameras, computer, etc etc.
The hell with traveling light!