The Best Way to Add Driving Lights to a Normal Car
After appropriate tires, the second most important safety upgrade you can make to your vehicle is a powerful set of lights
The stock headlights on your car or truck might work fine on well-lit streets, but they probably aren’t powerful enough to enable safe driving on completely unlit rural roads while motoring at or close to the speed limit. I detailed the solution—aftermarket driving lights—in a previous article but neglected to explain one thing: how to mount them to a normal car.
My wife’s best friend just moved to southwest Montana, where we live, and was in desperate need of additional illumination for her Subaru. Rachael is building her dream house in Madison Valley while working in Bozeman, a 60-mile drive away. As a mental health therapist, she often has to see clients after their own workday ends, which means she’s driving at night. And man, that drive is a doozy. Traveling from one river valley to the next, Rachael has to cross a mountain pass that’s positively treacherous in the winter, then follow a narrow, winding road through a canyon. Driving home after dinner at her place the other night, I saw two deer hit by other cars.
While Rachael plans to eventually build a modified 4×4—something much more suitable for driving conditions here in Montana—her house construction currently precludes that budget. I wanted to help make her drive safer by adding lights to her Outback, but lights typically require aftermarket steel bumpers or a permanently affixed roof rack to provide the necessary mounting points. This illustrates a problem that I think prevents a lot of people from being able to drive with adequate lighting: there is no easy, affordable way to attach them to a normal car. Or at least there wasn’t.
How far ahead do your stock high beams shine? Probably 100 to 200 yards. At 65 miles per hour, you’ll cover 100 yards in three seconds. That’s not nearly enough time to hit your brakes or swerve to avoid a deer or any other sort of obstacle. Slippery conditions, like snow, rain, or dirt, compound the problem. Why not just slow down? You should, but dropping your speed to 45 mph still only gives you four seconds to respond. People who drive out in the middle of nowhere have a real need for effective car lights.
Scroll through Subaru hashtags on Instagram, or visit owners’ forums, and you’ll see folks trying to solve this problem. Some bolt on metal bars that extend from the vehicle’s frame and out under the bumper, forming a hoop that you can use to attach lights. But this solution runs the risk of compromising the vehicle’s potential to shrug off parking-lot-speed impacts without damage. Bumpers add a cushion between those impacts and a vehicle’s frame, resisting damage outright and reducing the amount of energy that’s transmitted to the frame, but these metal hoops will transmit that energy straight to the frame, which could lead to damage, even in a very low-speed accident. By increasing the deceleration rate of the vehicle, it could also cause your airbags to fire in situations they shouldn’t. I really didn’t want to have to pay either of those bills for Rachael, so I ruled out that solution.
Others attach lights to roof racks or cargo baskets. But there are two problems that play into this: aerodynamics and reflections. Adding stuff to your roof destroys your vehicle’s fuel economy. And on lightweight crossovers like Subarus, which don’t tend to employ as many sound-deadening materials as heavier trucks, stuff on your roof also adds an awful lot of wind noise. Mounting a light source up high and behind your eyes is also problematic for vision. Even in spotlight beam patterns, driving lights are designed to provide a wide arc of illumination. Put lights on your roof, and some of that illumination will hit your hood and reflect back toward you. Drive through dust or precipitation, and those roof lights will also refract off those particles right in front of your eyes. Since driving lights are supposed to enhance your ability to see, not hinder it, I also ruled out mounting them to Rachael’s roof.
Ditch lights (ones that attach under the trailing edge of your hood and sit in front of your A-pillars) suffer the same problems as roof lights—and with even more wind noise. So those were out from the beginning.
There are some hidden light mounts available for popular off-road vehicles, like the Toyota Tacoma. With these, a light bar is mounted inside the vehicle’s grille, providing a visually neat solution that often requires very little modification. But they run the risk of altering the way air flows through a car’s carefully designed cooling system, and they may not perform as well as promised. I covered how to tell the difference between a genuinely effective driving light and ones that simply don’t work in that previous article.
To mount lights to Rachael’s Subaru without creating a bunch of problems, I knew I needed to find a mount that would position the lights in front of the car, where they could be most effective, and yet wouldn’t compromise her vehicle’s crashworthiness. Enter the Lightforce Unibar ($80). It’s one of those things that’s so simple, you can’t believe it didn’t already exist.
By mounting it to the existing license-plate bolt holes, the Unibar should be compatible with virtually any car or truck. And by attaching to the bumper itself, the Unibar also leaves that crash structure intact and uncompromised. The Unibar also positions lights in the ideal spot, right smack in the middle of the car’s front-most point. Its two mounting holes will work with pretty much any round, rectangular, or pod driving light.
My only concern was the strength of the bumper material that the Unibar bolts to. But since most bumpers are made from thick ABS plastic, which is designed to retain its shape for decades while resisting impacts, vibrations, and all the other forces experienced by a moving vehicle, I shouldn’t have worried. With the device attached, I’m unable to make it loosen or move at all, even when applying my full body weight.
For lights, I went with a pair of six-inch Lightforce Venoms ($658). Unlike some bigger names in the vehicle-lighting space, Lightforce actually tells its customers how its lights perform, with numbers pulled from independent, third-party testing. Providing one lux of illumination at 930 yards, a pair of these things increases the time Rachael has to respond to an obstacle at 65 mph from three to 29 seconds. Apply that to a situation like a deer crossing the road, and you can see the safety advantage that quality driving lights provide. With three seconds to work with, you barely have time to react at all; with 29 seconds, you have time to analyze the situation, come up with a plan for avoiding it, and then act safely. The result is simply transformative.
To set up the lights, I also used Lightforce’s $79 wiring harness. It provides everything you need to power the lights and allows you to operate them via your vehicle’s high-beam switch. Run them just like you would your stock headlights: Switch on your high beams when you need them, and the driving lights will turn on. Switch off your high beams around other drivers, and your driving lights will turn off. If you’ve ever rewired or installed an electrical outlet at home, you already have the skills necessary to do this. Expect the job to take about two hours.
A week or so after I gave Rachael her car back, she stopped by for a glass of wine. I asked her how many more deer she was seeing on her nightly commute with her new lights. In response, she just stared at me in wide-eyed shock. Shortly after, her husband purchased an identical setup for his car. Once you drive with effective lighting, you’ll never go without it again.