Kuyoyo 11 Apr 2019, 8:07 am #1412 Kuyoyo Kuyoyo Kuyoyo Posts: 6901 Threads: 43 Joined: Dec 2012 Reputation: 1 RE: Go North East: Upcoming Service Changes v2 Checking the registration number, the 55/55A/55X appears to be a renumbering of the X5/X5A.