I need a sleeping car.

我需要一辆卧车.

Is there a sleeping car attached to the train?

本次列车有没有附设一节卧铺车厢?。

A small private compartment for one on a sleeping car.

卧车的私人单人小房间。

A private compartment on a sleeping car with three bunks and a toilet.

卧车上一种有三个铺位和一个盥洗室的私人专用的卧铺车室。