行车记录仪的英语翻译是：dash cam。

关于行车记录仪的英语来源，我的知识是这样的：

行车记录仪（dash cam）是一种主要用于汽车上的视频监控设备。它通常安装在汽车前挡风玻璃上，用于记录汽车前方的影像。在英语中，"dash" 指的是汽车仪表板，而 "cam" 是缩写词，是 "camera" 的缩写。因此，行车记录仪在英语中就成为了 "dash cam"。

下面是一些行车记录仪的英文例句：

I installed a dash cam in my car to record the traffic on the road.

The dash cam captured the whole accident on video.

I always use my dash cam to keep an eye on my surroundings while driving.

Thanks to the dash cam, I have evidence to prove that it wasn't my fault in the accident.

Some people use dash cams to record their road trips and share the videos online.