I think modular parts would bring back the day of the Backyard Mechanic. Most of the cost or auto repairs is the mechanics labor to remove and replace the part that is bad. A lot of people that used to work on their own cars now won't touch them because of the complexity. If they could just remove a major part and bring it in for some work, it would save them a lot of money. I think I would want my repaired modular engine back, since it would probably be tweaked a little bit.;)

Wait a minute....wouldn't a skateboard configuration be exactly the same as classic body-on-frame design?

As long as some standards were added to the mix, I suppose so.

Kinda. Body-on-frame simply means there's a rail structure that everything bolts to. There's still open areas between the rails where various non-drivetrain components (such as footwells for the vehicle occupants) can be placed. All of the skateboard prototypes I've seen (admittedly, not many) have had the drivetrain components spread out across the board in an even layer... As if someone had thrown everything together, smashed it flat with some industrial rolling pin and then bolted suspension components to the corners. That approach doesn't leave spaces for footwells, which leads to the issue I was complaining about earlier - the footwells have to be built on top of the board and seats jacked up that much higher, resulting in every vehicle having the SUV or mini-van look.

Yeah, I just was reminded of this thread when I was reading this:
https://en.wikipedia.org/wiki/Body-on-frame
I don't know why I was reading it, I was kinda bored...nothing in there is news to me, I just hadn't thought of it that way.

Last I heard from a company that was working on the cooling system was that it required a whole lot of cooling to keep the fuel cell system from overheating to the tune of a couple of several thousand watt fan motors. Doesn't look like this idea is going to fly - too much wasted material - unibody is the most efficient form of body construction because the floor is also the outer skin - adding a few more layers to the floor just adds more weight.

Seems making the floor part of the skateboard might work. May need temporary cross braces to remove the upper part, though.