1、
第一句：Can I rent a car for just one day?
我想租辆车用一天，可以吗?
A: Excuse me. Is this car taken?
打扰一下，请问这辆车有人用吗?
B: No, may I help you?
没有，需要帮忙吗?
A: Can I rent it for just one day?
我想租这辆车用一天，可以吗?
B: No problem.
没问题。
2、
第二句：I'd like to rent a car.
我想租辆车。
A: Good afternoon, may I help you?
下午好，我能帮忙吗?
B: Yes, I'd like to rent a car.
是的，我想租辆车。
A: What kind of model do you have in mind?
您要哪种样式的车?
B: A compact car. I just want to drive around the city.
小轿车，我只想在城里转一转。
其他表达法：
I'd like to rent a car. 我想租辆车。
是租车时常用的句子，此处的rent也可以用hire来代替。
租车时还可以说：Do you have any cars available? 有可以出租的车吗?
此外，租车时要问清楚 Does the price include insurance? 价格包括保险费吗?等等。