Hello John, thank you for the trip photos and the write up.. very interesting.. Ref your issue with the wiper arms coming loose.. We had exactly the same issues on our Plus Six, they became a bit of an issue.. In the end late last year, I purchased a complete new set of wiper arms. I found that the old arms had become oval where they go over the wiper axle splines from tightening over and over again, as the side wedge pushes in and secures the arm to the wiper axle splines it has a tendancy oval the arms cap area.. The new wiper arm caps were much thicker where they go over the wiper axle, so it might be that MMC have introduced another change in that area??.. The change in thickness should resist the arms securing area going oval and thus the arm working loose with use. Since fitting I have rechecked the allan screw many times and only twice did they nip up a very small amount.. So far I have not yet resorted again to Blue locktite.. but maybe that is still needed for assurance. If you go past a dealer it might be worth taking one of your wiper arms off and comparing them with the new... just to check..
