OK, so are we all familiar with the OX? If not, it’s a low-cost flat pack truck designed by Gordon Murray (of course it’s middle drive), using some Ford Transit FWD 2.2 diesel hardware, meant for developing nations.
It’s definitely a real truck... and somewhere, I’ve seen suggestions that maybe it could work as a kit car. (In the US, you’d need a different engine for legal reasons, but I believe the Duratec 2.3 or 2.5 would work fine, and carry US certifications.)
...however, the damn thing is huge. Very lightweight for its capability, but huge. It’s about as wide as a modern full-size pickup, and significantly taller. (Length, OTOH, being a cabover helps a lot there.)
But, really, why couldn’t you just go... smaller?
Here’s my basic idea here. Reduce width to just enough to have a 4 foot wide bed. (Basically, I think this won’t be *THAT* much bigger than a Gator.) Reduce height through a lower engine and have the seat closer to the engine. (It’d be best if you could cant the engine over to an extreme angle, but finding a FWD drivetrain that supports that is likely difficult nowadays unless you go electric. Using a donor platform with an electric variant available isn’t a bad idea, but I think you’d want ICE options, at least.) Shorten the bed to 8 feet long (or maybe even less). Build it as a kit.
I think you could basically end up with something along the lines of a UTV in terms of size and maneuverability, yet as it’d be a kit, it could be registered on the street. Design it right, and while the freeway would likely be sketchy, 55 mph roads could be reasonable, with good payload.
I wonder how this would do, honestly...