I saw this Burgman for sale and noticed the top case. Although I think this is a little too big, does anyone know what kind of top case this is? I have a 2005 650AN-K5 and I need a fairly inexpensive passenger backrest with or without atop case that fits well and looks good. What is the top case with backrest of choice? Would any of the newer factory passenger backrest fit a 2005 model?