carriage, coach, car = wagon, wagon osobowy

Train car

Source: http://www.igougo.com/journal-j45407-Tbilisi-Georgia_Jewel_of_the_Caucasus.html

wagon, wagon osobowy

English sentence and Polish translation

Please, do not leave your carriage while the train is running. = Prosimy, aby nie opuszczać wagonu w czasie jazdy pociągu.