I always thought that all bmw’s are equally made and are fairly sensitive to corrosion (since the 2004MY when they changed into water based paints allegedly). I never really bought the story that two identical bikes, one rots and the other does not. Always thought it is each user’s methods that advance the rot or not. Well, until I experienced it myself. 14MY K1600, was prestine after 2 years and minimal dry mostly miles on tour. Acfd and garaged but never really meticulously cleaned. Its TB GSA 17my -same treatment, same acf bottle, same garage, was rotting within a few weeks and was fairly bad for its tiny 2k miles and 1 year with me. The MY 18 RT replacement of that which i have now with 4k miles and same everything, again. Looks prestine after 1 year (havent washed it yet to know exactly, but key points are clear). Weird. It must be how bikes are first assembled and perhaps stored at the factory or perhaps electrolysis factors in naked aluminum parts joined with other metals perhaps?