Here’s how you can unlock a car door with string (seriously)

I hadn’t done anything stupid or careless. I’d merely closed the trunk of my 1987 BMW 535i to pull some tools out of it. The car, which I’ve been driving frequently since I pulled its head and replaced its broken rocker arm this fall, was sitting in my locked garage, so the keys were in it, as is my custom. But, for reasons unclear, when I gave the trunk lid a good firm close, I was greeted by a noise I certainly did not want to hear: GSHWACK, the unmistakable sound of the central locking system engaging.

Like Kreiger in an episode of Archer, my first thought was “no no no No No NO!” I walked around and checked all four doors. Yup. Locked. With the only set of keys in it.

You know that feeling when you cut your hand and know that the next four hours of your life will be spent in the emergency room? This was a little like that, only less bloody.

I thought, well, I could wimp out and use my roadside service membership. I last did that when I locked the keys in my dear departed Porsche 911SC about 10 years ago. Because that car had smooth, recessed lock buttons, there was nothing for a coat hanger to grab onto. The guy sent to help me jimmied the top corner of the door open just a crack with a fiberglass wedge and reached in with a long thin rigid bar and hit a power window switch.

When I looked at the 535i’s door lock buttons, however, I was delighted to find that they weren’t like the 911SC or even like my BMW 2002—instead, they were the non-recessed golf-tee-shaped kind. I hadn’t tried to coat-hanger my way into a car in years. I thought it would be fun, in a MacGyver kind of way. I found a coat hanger and bent a hook into the end. Then, remembering what I saw the service guy do years ago, I used a pair of rubber-handled pliers to jimmy open the upper corner of the door and give some clearance for the coat hanger.

But I was not successful. I spent nearly an hour and a half trying to maneuver the bendy coat hanger into position. Once I even got the hook under the lip of the door button, but it slipped off when I pulled up. I was never able to get it into position again. When I saw I was beginning to scrape the black anodized paint off the edge of the door trim, I stopped.

I posted my failure on Facebook and folks sent me some good suggestions. One was to go to the dealer and get a duplicate key cut, something which I clearly needed to do anyway. That was a good idea, except that I’m not on a first-name basis with the parts people at the nearest BMW dealership, so I’d almost certainly need the registration or title to prove that I owned the car, and the registration was locked in the car, and the new title in my name hadn’t yet been sent to me by the state of Massachusetts.

Another suggestion was to try “the string trick.” Someone sent me the link to this video. I watched it and was surprised I’d never heard of this technique. According to the video, you simply make a slipknot in a piece of string to create a loop, slide the string around the upper corner of the door and work it past the door seal, and, using both ends of the string, maneuver the loop over the push button. When it’s in place, you pull both ends of the string to tighten the slipknot, and pull the string up to unlock the door. Although the video doesn’t explicitly say it, the idea is that the string method is superior to the coat hanger method because 1) the string’s lack of rigidity makes it easier to get it past the door seal, and 2) you can control the string from both ends, which makes it easier to maneuver its loop over the door lock than the ungainly coat hanger.

OK, I thought; it’s worth a try. Besides, my car buddies would surely challenge my manhood if I called someone to unlock the car.

Obviously, step one was laying my hands on a suitable piece of string. In trying to do so, I experienced one of those moments when you tear the house apart looking for something you know you have somewhere but can’t seem to find. No string in the house. No string in the basement. No string in the garage. It was ridiculous. Coming up empty-handed, I resorted to pulling a shoelace out of an old hiking boot. This turned out to be a poor choice because it was a flat lace, the impact of which will be explained in a moment.

I tried to slip the string over the corner of the door and get it past the door seal. This turned out to be far more challenging than in the video. I used the rubber-handled pliers to wedge open the upper corner of the door, but the shape of the door seals on the 535i is such that the string falls into a deep lip in the seal. Using the coat hanger, I was able to poke the string past the lip and could pull it down.

Next, I tied a slipknot near the right-hand end of string. A more specific video showing exactly how to do that can be seen here. I pulled the left end of the string to slide the slipknot past the door seal. One thing the video doesn’t tell you is that you need to make the knot in the slipknot very tight so it doesn’t slip while you’re doing this step. Fortunately, if the knot pulls closed, you don’t need to start from scratch; you can just tie a new slipknot near the right-hand end of the string and try pulling it through again.

Now, it was a matter of doing what’s shown in the video and maneuvering the loop into position over the door lock. In my case, there were two issues. One was that it was very difficult getting the string past the part of the door seal nearest the windshield. I had to pull the string so hard that I was concerned I’d rip the seal. But the other issue was that the shoelace I chose was causing a problem. Because it was flat, I couldn’t rotate the string by arbitrarily small amounts; it always seemed to want to flip 90 degrees at a time. This made it particularly challenging to get it around the door lock button.

But after several attempts, I was able to guide the loop where it needed to be, cinch the slip knot, and pull up the button. This time I heard the central locking system’s characteristic GSHWACK, my response wasn’t “no no No No NO,” it was “yes yes Yes Yes YES!”

In the short term, I’ve taken to not leaving the key in the car, even when it’s in a locked garage. And, yes, I will get a duplicate key made. But I also know that, if I’m wearing shoes other than loafers, I’m good.