这句话中的系动词用得对吗?For American it’ s hard to imagine living in a place where there is no cars

对

For Americans it's hard to imagine living in a place where there are no cars.

对啊
这是it做形式主语的句型啊
it is +形容词+to do

对啊

对，两个都对
it's hard to.... 强调句式
there is 。。。。做where引导的从句 is 要改成 are

For Americans 要用复数
另外 此句子正确

顶楼上的楼上 hard换成 difficult car换成 vehicle就更好了

没错.
但有其他错误：
美国人的复数应该是Americans,后面应该是where there is no car,用单数,或者there are no cars
no=not a（+单数）或者not any (+复数)

there are no cars