The English term for a small car is "subcompact car". The term comes from the fact that a subcompact car is smaller than a compact car. Here are some example sentences:

I just bought a new subcompact car.

Subcompact cars are great for city driving because they're easy to park.

The fuel efficiency of subcompact cars makes them a popular choice for commuters.

In Chinese, "subcompact car" can be translated as "小型汽车" or "小型轿车".