Do you notice something missing from the side of your car every time you signal to change lanes? Were you backing up into or out of a parking space without looking at both sides of your vehicle? If so, then it's likely you've damaged your door mirror glass or completely busted the whole door mirror. This is quite a common occurrence, and almost everybody at one point or another has suffered the trauma of breaking one (or both) of their side door mirrors. Who knows; you may have purchased a classic vintage car in need of restoration, and it may have been missing a door mirror or two that you need to replace. Either way, driving without a side mirror is dangerous and leaves open the possibility you wouldn't see a car next to you if you want to change lanes. That means that you need to get a new door mirror on your car - pronto.
Initially called "wing mirrors", automotive side door mirrors have been a part of motor vehicle safety and convenience since the early 20th century. They are integral in providing the driver with a view of both sides of the car, as well as the lanes next to them and the car behind them. The first cars to use door mirrors only had one. On some models it was on the driver's side, and on some models the mirror was on the side opposite the driver. It became common in the 1960's and 70's for cars sold in North America to come with the option for door mirrors on both sides, however it wasn't until the 1990's that it was required. Nowadays, door mirrors come with electronically adjustable controls, heated coils that keep the glass from fogging up, integrated turn signals, automatic folding mechanisms, and electrochromic dimming to minimize the reflections of bright lights at night.
If you simply need to replace the door mirror glass, this can often be done with the mirror on the car. You would simply remove the glass panel and install a new one in its place. There are even glue or stick on alternatives that will install over the cracked glass. However, it is not this simple for everybody and replacing the mirror might be your only alternative. Changing a door mirror is fairly easy and straight forward, and shouldn't take too much time as long as you have the appropriate tools.