"Hit one's head against a car" 或者 "Bump one's head against a car" 都可以用来表示头撞到车。这个表达方式来源于英语中表示身体部位的动词和名词的常见用法。
下面是一些可以使用这种表达方式的英文例句及其中文翻译：
"I hit my head against the car door when I was getting out of the car."（我下车的时候头撞到了车门。）
"Be careful not to bump your head against the car when you're getting in."（上车的时候小心别头撞到车上。）
"She accidentally hit her head against the car roof while trying to put her luggage in the trunk."（她放行李箱的时候不小心头撞到了车顶。）