Have you seen that TfW have taken to running road coaches, both as crowd busters for full and standing trains (not that a 50 seat coach or two will make much of a dent), and pre-booked for sports fixtures. Such is their confidence in their own train service.The even more crazy system is to run buses instead of trains, don't sell tickets and still pay their drivers and conductors. TFW's losses must be crazy.
A Mk4 set will however spend all weekend in the carriage sidings at Holyhead.