Harassenger is a passenger who is constantly judging your driving skills. He/she constantly cautions you to keep a safe distance from the car in front of you, checks that you're obeying the speed limit, and is always quick to point out your navigational errors.
Harassenger（harass和passenger二词的合成形式）指坐在你车上并不停对你的驾驶技术挑问题的乘客，大家可称为恼人乘客。他/她会不停地提醒你与前车维持安全距离，查询你的行车速度是不是在限速范围内，而且总能非常快指出你的导航错误。
For example:
Guy riding shotgun: Could you slow down a little? We're dangerously close to exceeding the speed limit by 5 mph.
副驾驶座位上的乘客：你能否开慢点儿？大家非常快就要超速5迈了。
Driver: Quit being such a harassenger.
司机：你快别烦我了！
