Long distance routes do not take up that much room - most people don't do it often enough. You wouldn't want this for getting to work every day - that wouldn't work. Though a train car can safely follow closer than a auto so it would still be better than private autos.
From what I remember they ran that car on banker/stockbroker hours - the average commuter would have never seen it.
Part of the draw, I'm sure, is that Metra allows alcohol on trains. So you've basically got 50+ friends drinking together on the way home, every day. Speaking of which, I thought I heard something about them bringing back the bar cars to increase revenue. (For those that don't ride the train in Chicago - it is BYOB. In the old days they actually had a public train car with a bar and bartender you could purchase from).
End of bar car was sad. They did have bars in the station that would sell in Togo mode, which was mostly good enough.
It’s not unprecedented.
https://en.m.wikipedia.org/wiki/Car_553