I acquired the tank bag when I purchased the 2009 R1200R from another member. The bike had only 2500 miles on it and everything was great except for the fact that the tank bag had already caused discoloration on the white gas tank. I wasn't too worried since I like to have the tank bag on at all times.
I purchased the bike last November. As the weather warmed I rode it as frequently as possible and the map window started to yellow. Then, during a 5000-mile trip to Wyoming and back during the past two weeks, the plastic became brittle and broke when I inserted a map. The flap of plastic then broke off in the slipstream and left a gaping hole.
I noticed as I gassed up each time that the bag is leaving gooey skid marks on the gas tank from the rubber padding. I didn't spill gas on it. Like the plastic map case it just seems to be made from inferior material.
Meanwhile, my BIL was riding along with me with his Marsee tank bag with original map case clear and clean after 40 years of use.