I have a plate on retention and have done for some years, When I last asked Mb if I could use it they said no, because it bears no real meaning to my daughter. I’m just her appointee/named driver??
They’ve relaxed the rules on private plates. They no longer have to relate to the benefit recipient. My wife is the Motability customer but our private plate is my initials. I just told them I was assigning it to our car. No issue at all.