I like the idea but wonder how big a can of worms that could be? One of my gripes about my Scrambler (and my Bantam trailer too) is trying to carry a 4x8 sheet of plywood. I don't know the measurements off the top of my head but do they really have to be so large? Is there some other way to design them to allow more room?
A few weeks back I had to transport a Safari Cab roof from South Carolina back to NY. At roughly 58" x 7' 2", it's slightly too large to fit inside the trailer, and slightly too small to fit easily on top of it. So I attached some 2x3 load bars to the top of the tub using the hardtop holes and screws, and put the roof on top of those.
Carrying a 4x8 isn't too hard on either of the sizes of trailer I've pictured in my trailer tub kit concept drawings. For the longer of the two trailers, a 4x8 fits almost all the way inside, the back of the sheet rests on the top of the tailgate. For the smaller trailers, the load bar idea works great.
My plan for the trailer tub molds is to have the molds long enough so the side panels could be 8' long if desired, that would end up with an 8' 7" trailer, so a 4x8 would fit flat in one built that size, especially if you built the wheel wells as I did (see below).
If not i would fall back to my second jeep thought. Why don't we get the wheel well storage area anymore? If the wells have to take up space, why not make them a minimum height and create a full floor out out of it and put I'n access hatches. Be a great place to store recovery gear, small parts, tools, etc... Just a thought.
On a trailer the wheel wells can be far smaller than on a vehicle because the wheel travel is much less. On a vehicle the wheels articulate into the wheel wells, on a trailer generally the whole trailer rises over obstacles with much less wheel articulation, so there's far less wheel travel relative to the wheel well.
In my trailer, I added a few inches to the track width, so there's 49" between the inner fenders, unlike the Jeep tub, where there's 37" between the inner fenders. My wheel wells are still higher than they need to be given the limited articulation that the trailer has, so they could have been made shorter, but since there's 49" between them, I didn't see the need.
So my trailer has a 49" wide by 7' 5" clear floor area, which allows for carrying large items. And with the load bars, I can even carry an entire Jeep tub - that was one of my design criteria for the trailer - the ability to bring a Jeep tub home in the event of a future project requiring one. Another requirement was easy carriage of 4x8 sheets, and a third requirement was easy carriage of very long things, up to 16':
And with the 3000 pound load capacity, I don't feel like there are too many things I could ever want to carry that I couldn't carry with this trailer.
What have I missed?