In my experience, there are very few bags that are truly dry. That includes many manufacturers' bags, like some BMW, and lots of the aftermarket choices. One of the driving forces for water-resistant bag inserts is to keep off the water that inevitably seeps into the bags. All you can do is adjust the hinges and latches, check for good sealing, and improve, replace, or shim the weatherstripping, if needed. Add inserts or ziploc bags if that doesn't work. The RTS seems to be an exception. My bags and trunk have been tight so far, but I haven't ridden in that tropical, torrential stuff you get exposed to.