We play quiet when the train pulls into the station (as you saw in the video), so as not to attract undue attention. Other passengers obviously get what's going on, but why draw the authorities in unnecessarily? That's a bike trailer at the end with the regular soundsystem on it. It's normally towed by a recumbent, but we left that at a safehouse near the station. Under the tarpaulin is the second one we recruited on the night (more on it later).