TANK RUST: I used to have a K, but actually learned this the hard way on an R100 GS: BMW tanks rust! I couldn't ride for a couple of years, left the tank mostly empty, and stored the bike outside under a raincover. (That's three (3) mistakes!) The tank was a mess inside. I bought cleanout / re-coating stuff at the dealer, which seems to have worked. Had to pull the tank, fill with hardware, shake all rust out, buy corks for the orifices, degrease, degrease, degrease, then re-coat. Moral of the story: fill the tank with gas and put in fuel stabilizer to minimize rust during the winter. Store bike inside.