英语翻译Cars already play an important role in modern society帮我看

不对.
你既然用了already ,就说明应该是现在完成时.你的没有助动词和动词的变化.应该为：Cars have already played an important role in modern society .

Cars have become an indispensible part in modern life.

有点语法问题
Cars have already played important roles in the modern society

Nowadays,cars have become an indispensable part in our life.