Backup cameras will be required on all new cars sold in the U.S. as of May 2018 but, in the meantime, you could end up buying a car that doesn't have one or has a lousy one. Take the advice I've learned reviewing 1,100 modern cars and avoid both of those pitfalls.
- Get a camera. A fair number of cars only offer a rear cam as part of an expensive a la carte or option package selection. (I'm looking at you Germany.) Keep that in mind when shopping cars and checking boxes. You definitely don't want to settle for a car without a backup cam.
- Check your trajectory. Most cams today generate some kind of overlay lines that show you distance and steering trajectory. These help you estimate what's in your path, since backup cameras are very wide angle and that distorts the size and shape of what they show you on the screen.
- How's the image? We don't see a lot of low res backup cams any more but since carmakers rarely publish resolution specs the way cameras and phones do, look for crisp details (a function of both camera and screen quality) as well as good day and night handling ability (admittedly hard to gauge in a test drive).
- A new angle on things. Some cars have cameras with switchable angles, from wide to very wide to straight down views. I find I don't use these after a while because it's one more fiddly button you're not going to bother with after the novelty wears off. Any standard wide angle is very good, no need to switch the view.
- Other cameras. Surround cameras are fairly common and stitch together a birds eye view of your car, like in a video game, using cameras in the back, front and sides. These are nice for big vehicles, but remain in the "non-essential" category in my opinion. More interesting to me is Honda's LaneWatch camera that looks down the side of the car opposite the driver, where you are at risk if pinching a bicycle, etc. It offers a more comprehensive view than side mirrors do of a place where a lot of urban warfare takes place. If you're considering a Honda, ask to try it out.
If you already have a car without a backup cam, adding a wired one via a smart mirror is cheap, though kind of a PITA. Another new option is the Pearl license plate frame that beams a wireless rear view to your phone. Not cheap at $500 but they know what a PITA the other options are.