Evening Jon, yes I did consider the old arms to experiment with, they would certainly be easier to work on.
Ref motor being poor.. again it is a possibility, the car has always had wiper judder issues since we purchased it with 500 miles on the clock. I have made headway today though, still not 100% but its certainly getting better. The wiper system was surposedly all replaced by the factory, but I only have a verbal dealer conversation on this and I do not know if they meant the motor as well. Nothing in writing to me ref work done for both warranty visits to the factory and I have no way to confirm 100% if the motor was replaced.. The factory seems to be a black hole to owners when it comes to information like this.
Of general interest, as per Lornes posted info. I have acquired a picture of a wiper motor taken from a 2019 Plus Six that was being broken for parts following a fender bender.... this states it is a Britax PSV PSV900-12L wiper motor, the picture shows a big Britas sticker on it with "Tested in the UK" of course this means nothing, as it does not say made and tested in the UK.. also its also possible the factory may have used another brand as my car is almost a year on from the first 2019 production..
