Also above, someone notes that the doors rattle. This drives me nuts. I usually jam a coathanger in the door track and it helps. This makes me thing a $0.25 bowed piece of metal acting like a leaf spring, mounted inside the door track, would keep the door pushed against the other side of the track and stop it from rattle. Or a couple pieces of sacrificial plastic, again less than $1, that are changed out 1x/year. If they weren't screwed in, perhaps work rules wouldn't prohibit a car attendant from swapping them out.
The new Acela: It's not Aveliable.