（2）后视摄像头/倒车警告系统

    美国国会早在2007年就要求私家车必须安装倒车摄像头，不过美国国家公路交通安全管理局（National Highway Traffic Safety Administration）已然数次推迟了强制安装倒车摄像头的法规。但是倒车摄像头对我来说太必要了。有了它之后，你只需要对着中控台上的屏幕以及屏幕上的黄色倒车线进行操作就行了，这比扭着脖子朝后看有没有盲点要安全得多，另外还有非常有用的“滴滴滴”的声音，提示你是否离后面的东西太近了。

2. Rearview camera/backup warning system

    Several times, the National Highway Traffic Safety Administration has delayed rules for rear visibility that would require backup cameras since Congress required them in 2007, but they can't come fast enough for me. It is much safer to watch a screen on your dashboard that has helpful yellow guide lines than to twist your neck over the back of your seat, look around for blind spots, and then try to back up. And don't omit those helpful beep beep beeps that let you know when you've gotten too close.

    It's a radar-based system that detects vehicles travelling in parallel lanes and uses blinking lights in rear-view mirrors to warn when one is in the blind spot. It's very helpful in preventing you from veering into occupied space, along with the attendant horn-honking and name-calling. More advanced intervention systems apply the brakes to nudge the car out of danger.