I haven't mounted a Shad case, or any topcase, but I got my local scooter store to put a Givi sidecase mount on my rear rack so I could put a Givi sidecase from my motorcycle on my People. Generally, with the universal plates, you'll have to drill a hole or three in the scooter's rack, and usually you want to put some glue or threadlock on the bolts that hold the mounting plate on. Both for holding fast and for security. So go with at least red threadlock, and if you don't mind committing to replacing the rear rack if anything goes wrong with the case and plate, you could epoxy it?