Well...it rained during my test drive and there wasn't a single wet spot inside the trailer!
Guess that means I can be confident that any cargo I store in there should be dry from any storms that I might encounter.
I have a few more adjustments to make to the trailer before I'll be ready fer the road. The gap cover rails on the truck will have to have the bottom corner knocked off as it's still digging into the trailer lid...which shouldn't take very long to lop off in the morning.
I will base the remaining truck/trailer bottom gap cover off of the extended rear diffuser since it's already got a solid support system in place.
I will have to drop the trailer back down to the middle (3rd hole) on the hitch (lowering the front of the trailer). This will mean the access doors will have to be trimmed/rounded on the front edge a little...either that or I will have to load the trailer on the street instead of the driveway as the chin-pan-easy has been contacting the driveway on the test drives on the 2nd hole on the hitch.
I will need to install an on-board 200psi air system so I can easily air up the air shocks (or anything else) without looking fer a gas station with a decent air compressor.