I wouldn't suggest putting too much weight in it, I'll just use it for bulky lighter things like clothes etc on a trip, and keep my heavier items in the side cases. I know there are warnings and weight limits etc, but in 5 years of owning this bike and being on many forums I've yet to see any posts/reports of somebody cracking or breaking the passenger grab rails due to an over loaded trunk...
yeah, but nobody was silly enough, or had enough $$ to buy that bigazztrunk.,
just kidding...
well, it is a bigazzed trunk... dude.... really?
do the trailer thing like I did... and you can color match it to look cool.... twice as much paint, and no overhanging doppleganger...