So finally back to the semi frozen north after 3 awesome months in the southern USA. I bought my Xmas present and only got to see it myself two days back. My new BMW Soft Bag GroB 3. Ordered it through my Calgary dealer so they are available locally in North America. I paid $297cdn all taxes in. Is simple to mount and has a pocket that captures the tail end of the stock top box mount then straps hold it forward. I use another set of straps to hold the back end forward for safety. All in all a great addition. I can't remember if it is 50 or 60 liter capacity but it does zip out to expand at the ends. Has carry shoulder strap, fold away carry handles and 3 pairs of mounting straps. Stiff back for pillion backrest. Will update once we utilize it.