Howdy, Theoplus! I recently added this system to my Plus. The local dealer is no longer a dealer, so I ordered them from the one in Colorado. Just checked, Foothills BMW/Triumph, in Lakewood. If you have a local dealer, go with them.
They are Givi monokey cases, the rack they mount to is meant for the Enertia, it doesn't seem to be generic. Unless it is generic, and Brammo built the bike to match the rack... possible, but no idea which is correct.
They do have a fairly light limit, and the structure does not support a topcase. Considering how driving over 45 cuts range significantly I wouldn't want to add too much weight on the back and reduce range further. The rack itself is hefty... I didn't weigh it, but I'd guess in the 5 to 7 lbs range, perhaps?
Incidentally, I found the measurements on the cases were a little optimistic, the width and length is measured at the mouth, not the bottom, which tapers smaller. I bought them to carry two laptops while commuting, and the larger of the two would fit if the dimensions listed were at the bottom. So, sizable expense for a case system that I cannot use for the intended purpose, unfortunately. Also, IMO, for the cost, the Givi cases are a little flexy compared to BMW cases, which only cost a fraction more, it seems. But, again, for lightweight stowage, they'll hold up just fine, my comment here is that I'd hope for a more rigid build quality for the price.
If you want accurate measurements at the mouth and the base, I'd be happy to go grab a tape measure.
