The first example is like the one I have. Cut in half and plan-tapered it would be a good fit for a VW Beetle, which is 42" across
above the rear axle line. I chose not to cut mine up.
The second one could be quartered and spread at the front, horizontally and vertically. It would be a big step ahead of the square-framed box you started with. I'd put the lower section below the deck.
I notice you haven't put the wheelbarrow to The Template. That would be a first.
