I've done several sweeps of the cab and can't find anything. I tried watching back last night's stream but Matt just used keyboard shortcuts, super useful for console players...
When facing the back of the cab take the door on the right, the switches are just through the cab door on the left wall. Matt showed it a little bit further into the run.
Thanks! I didn't really want to skim through the whole stream. They're always so well hidden, it's gonna be a challenge remembering all the different locations for each train!