A house IS a simple thing - it is not the case that you only have a few companies in the world that make a "good one." To me the thing that separates rail from

A house IS a simple thing - it is not the case that you only have a few companies in the world that make a "good one." To me the thing that separates rail from cars or other vehicles is that they have the advantage of having railroads, and so I would think that they can make additional assumptions that cars can't. They don't need the steering column for example, or make too much fuss about differentials. And yet, the fact that cars are commoditized, but there are only a few good rolling stock companies in the whole world makes me wonder what I am missing. Maybe the demand/volume is just so low that there is no opportunity to commoditize or create a huge market.