I wanted some extra space for small quick item's without over-doing the cosmetic's of the DT 300i. Looking around I found the TourMaster CRlll Nylon Toolbag. I selected this particular bag being on the back of it, it's mounting strap's can be positioned either in a vertical or horizontal postion for tie down to the horizontal bars on the Back of the DT Rail's. I purchased the Nylon Style being they match up better with the scooter and are not so stiff as the leather one's. About possible rubbing, I placed velcro (soft side) patche's on the part's of the bag that will rest against the rail. I don't have them on yet but will shoot pix's to display on here. To view this particular bag....
http://www.tourmaster.com/xcart/product.php?productid=310&cat=0&page= I'll use mine for probably the water bottle some quick tool's or whatever these handy bag's will hold.
