Covering half of one long side and the end would make a perfect windscreen! Paint two sheets of light weight steel and pop rivet them on! Put the point into the wind with an umbrella on the corner, should be pretty well weatherproof!
I really like this as a starting point for “ultra modification”. I’m really reconsidering abandoning my original windscreen concept for this!! Not a lot more money and it’s a steel cart to boot! The mind boggles!