EDIT: I originally misidentified these cars as "light rail." doinky corrected me, saying that "These aren't light rail vehicles; they're diesel multiple units (commuter rail vehicles)." I've edited the title of this post to reflect doinky's correction.
I saw two of these cars at the Capital Metro building near the train tracks. The guy in the orange vest yelled out to me to stop taking pictures. I smiled and waved at him. Click here to see more pictures.