Victor, there is something that we think and express  and what they speak in natural English.
So, it´s way more natural to say "women-only passenger car" or "women only carriages" (in speaking English - if you are elaborating about it).
But as they like to keep it short (and simple) in English you can see the train cars with signs with "women only" (you can try Google image to see some of them).
 even if they understand. They might see what you meant, but they will know that you are not fluent enough in the language, or you are a beggining ESL student. Or it might not matter at all, because you are a tourist spending some money.
Anyway you won´t change their language to fit yours, at that moment the a native will think to himself that you are "tripping over their language". And worse, sometimes you will misunderstand, because you are not used to a more natural way of speaking.