Update: test run
Today I needed a tube of caulk and some 1x2s to make a floor in the tail. My brother was heading off and so I had him follow me for a mile and watch the light snow flow off the tail. Then we swapped cars I and watched. I also took a video clip (not sure how to embed so here is the link) :
Nothing fell off on my trip into town. I taped the gaps and the tape held just fine.
I also took some pics:
snow build up, so I think this area could use some help:
Ideas?