I have a 99 R1100RT which I bought last year. It came with an original BMW tank bag, not sure of the specific model, but it is not expandable and has the snap on plastic map holder. Did not come with a separate rain cover, so I don't know if it was missing or maybe this thing is supposed to be waterproof. Looks like it could be save for the map holder. Does anyone know if these bags are designed to be waterproof? Getting ready for a big trip and do not want to take a separate rain cover if I don't have to. Thanks...