Caption: The CN TEST Track Evaluation System train that I saw September 11th was re-encountered on the 17th.
It arrived at CN Bayview eastbound off the north track of the Dundas sub, continuing onto the Oakville sub.
Later that afternoon it pushed back to Hamilton Jct, and returned westward via the Cowpath as seen here.
Burlington Bay and western Hamilton are in the background.

The lead engine, ES44dc CN 2274 has a white rectangular box above its headlights which looks like an outdoor security camera, and a dashcam-like device inside the left cab window. GP38-2w CN 4791 has a squarish box on the nose beside the C of CN, with a cable running back to the boxcar.
The modified boxcar is CN 414852 "DGRMS Test Car". The TEST Track Evaluation System coach is CN 1057.