The last leg of the long way home

Rail travel on UK is not a speedy option, but not driving and chilling out a bit is good. The 3pm train from Leeds arrived in Glasgow Central at 8pm. The huge train time board announced the train to Kilmarnock was leaving imminently and the rear 2 coaches were going through to Stranraer.

I spoke to the guard as I approached the train positioned on a slightly curved platform so the end of the train was not clear in the dim light. 'Which 2 carriages are the 2 rear ones?' I asked politely.
He looked confused, then started laughing. 'There's only 2 carriages, hen!'