Most importantly, try SHOVING a bunch of passenger cars through it.
That could be interesting.
I'm not a passenger car guy, the only ones I own are the Penn Central's recently released by Kato, so I don't know if how the Kato cars behave is indicative of all passenger cars or not.
Anywho, I was surprised how light the Kato passenger cars are– I mean very, very light.
Secondly, the wheels are slightly too narrow, which is a potential bug-a-boo on Atlas code 55. Between the their light weight and narrow wheelsets, it could be quite an adventure trying to back these cars through any sort of code 55 trackwork, but some complicated passenger terminal trackwork? Hmm.