Since buying my K1300S last fall I've been trying to figure out a way to get a 'real' topcase on the bike... a Givi to be exact. I've been using Givi products since a 22L topcase fell off my K100RT many years ago, and before Givi even had a US importer. I have clearly been incredibly happy with their product.
I faced a dilemma: how do I get a Givi topcase on my K13, and should I wait to see if Givi comes up with a kit? I waited through winter, but now riding time has arrived and I have trips to take. I ordered the Givi K1200S kit thinking it ought to line right up. I was wrong. The top tail piece of the K1300S flares out to match the lines of the body, while the K1200S has a narrow tail section. I screwed up some courage, checked with the dealer that I could order a new top tail piece (I can, its $70) and then started to work modifying the tail piece to accommodate the support brackets that bolt into the rear subframe of the bike and the back of the Givi mount plate, which in turn bolts to the BMW side case arms and luggage plate.
Here are some prelim photos of the final result. I'll get some outdoors in daylight tomorrow (assuming it doesn't rain all day as predicted). I hoping to get out and ride tomorrow also and see how it handles: