if you can find some of the "C" shaped cross section "edge strip" like what is used on the edges of the C10 fairings, it could easily be bonded to the trunk using 3M double stick trim tape... strong stuff, and the divider could be cut from a piece of plexiglass to slip into place in the "C" channel... easily removed when necessary.
like this stuff from mcmaster carr.... about $3 worth would do the trick....
type 1 here,
http://www.mcmaster.com/#trim-molding/=z5gk5yspecifically this one
http://www.mcmaster.com/#24175k14/=z5glazor even cheaper, Home Depot, clear plastic drywall corner edge protector anglenstuff, a couple pieces strategically located to make a channel, and bonded in place with that 3M trim tape...
like this stuff...
http://www.mcmaster.com/#standard-plastic-angles/=z5godgstrongest bonding adhesive you will find that will stick to that plastic
I've used this to bond a neoprene back rest pad to my Shad trunk.it seen allnsorts of bad weather for over 10 years... it ain't coming off....