I've now got the end plates made and fitted.
...with the teenuts epoxied in place for the 6mm holding screws. The two pairs of handle on each end give carrying options for both orientations. The tall thin orientation will be necessary to get through the average door.
I managed to heft it out to the car on my own and try out the fit. The first way was lengthways into the car...
...which came up to the seat hinge line...
...which definitely meant that I couldn't get the seats folded back up. I then tried it broadside on with a height of two feet...
...and it fitted quite easily with more clearance at the seat hinge line..
... but it just needed another inch to give enough space for the seats to lock back in their normal positions.
I had hoped to fit the boards in the back of the car without putting the seats down, which would have been in the broadside position with a height of 2' 8", but I got thwarted by the narrowing of the rear doorway at the top - by an inch.
I haven't quite given up on that position but will wait to try with someone else to help. It might be possible to load the boards at a slant to avoid the narrow top of the doorway, then return them to the vertical once inside the door.
As a side issue, I used Devcon 2 ton Epoxy which I had got some time ago as a quick setting epoxy from the local B&Q. Both tubes were half full of air and I had to squash more than half of them before I got anything out of the nozzles. I can't remember what I paid for it, but I now suspect it was not a good buy. And the tube caps are the same colour so that's a disaster waiting to happen.
Jim.