I have the Utopia driver's backrest installed on my RT. I'm looking for the largest luggage that I can find that will fit on the passenger seat with the backrest installed. Any clues? It seems like I only have around 8 inches in depth for the passenger seat, which isn't much space for a bag.
Jon,
I've decided to try a compression dry sack (Sea to Summit) which is about 10 inches in diameter and about 23 inches tall but will compress down depending on what I pack. Might want to look at the various sizes of the Sea to Summit or other dry bags available. Most are advertised as being water proof and being soft can most likely be squeezed into the space you have behind your backrest. I have an Ultimate seat w/ backrest which gives me a little more room than your setup. Good luck with your search.