Pleased to report my Plus Four (MY22 spec) has now had the fix applied (replaced Master cylinder and "swirl pot" installed) and is at last back on the road after 10 week hiatus. Many thanks to dealer BHM for their tenacity in working through all the problems in understanding the issues, vehicle recovery, actually getting promised fix kits etc. Hopefully parts availability will be improving now so that we can all get back to enjoying our cars.