I was driving Northbound on the M5 today (tues 29th) and on the bridge near ROwley Regis station (just before J2) I saw a passenger train on the bridge with white/silver carriages. The word 'mainline' was written on them and there was a DB Schenker loco at the rear. The timing of the sighting was 20:08. Please can anyone shed any light on what this train was and the journey it was making? Never seen it before. Thanks!