Depends on the car. For passenger cars, not really, because as mentioned they would be too cramped inside to game (though I would prefer transparent/cut-out windows... but those can be converted with effort if you do make closed passenger cars with solid opaque windows), but for goods/box cars, yes, as the space is open and therefore enough to be worthwhile
and if it's a car with sliding doors on both sides (as they usually are) you can open them up to change the way the car might be used as cover (possibly even opening them in-game).
Also, I am excited about what this poll question might mean!