Safety upgrades for your car

Today's new vehicles are brimming with advanced safety features. Blind-spot monitoring, for example, helps keep you from hitting an unseen car when changing lanes. A forward-collision warning system signals if your car is in danger of striking one in front. And a lane-departure system alerts you if you begin drifting out of your lane, which might happen if you're distracted or sleepy.

Now you can get those safety features for your current car. We recently evaluated two products: the $850 Mobileye 560 and the $250 Goshers Blind Spot Detection System.

With Mobileye, a camera mounted behind the inside rearview mirror "reads" the road ahead, monitoring such things as lane markings and the distance to the car in front. Using a built-in speaker and a small display unit, it will give you audible and visual warnings if your car begins leaving a lane, you're following a car too closely, it senses a pedestrian or bicyclist, or it calculates that you need to take action to avoid hitting a car in front. The system can also switch your headlights from high to low beam for oncoming cars and read speed-limit signs to signal if you're going too fast.

The sensitivity of the various systems can be adjusted along with the volume of the audible warning, and each function has its own audible and visual warnings.

Some functions can be turned off if you find that they're not useful. A smart phone can also serve as the system's display by using a wireless Bluetooth connection and a separate Mobileye app.

Overall, we found that Mobileye's features worked well and gave us ample time to react, on the road and in simulated situations at our track. But staff members noticed one annoyance: At speeds faster than 19 mph, the display constantly shows the number of seconds—up to 2.5—that your car is behind the one in front.

Mobileye needs to be professionally installed, which adds about $150 to the cost.

The Goshers system is designed to do only one thing: alert you to a car in your blind spot. It uses sensors mounted on each side of the rear bumper, corresponding warning lights for the interior, and an audible alarm. We found that the system reliably warned us of other cars but that it can be a bit overzealous, with guardrails and other objects causing false alerts. It was more helpful when we adjusted its sensitivity to its lowest setting and opted to get warnings only when a turn signal was activated.

Installation took our mechanic about 4 hours. We don't think it's a job for the average do-it-yourselfer.

Overall, both products can help you avoid crashes, although neither provides the visual and functional integration of a built-in system. And neither is a replacement for maintaining a safe following distance, checking your mirrors, and looking over your shoulder when changing lanes.

See our guide to safety for more information about vehicle features and crash avoidance technologies.