Hacking a $45K Mercedes-Benz in the Name of Utility


Warning: this post is not for the neat freaks and careful souls that put plastic on their furniture. It might offend those that like to keep their expensive cars in showroom-floor-fresh condition. If a thought of tearing apart a fine $45,000 automobile is revolting then you might want to skip this one. For the rest, lets delve into one of my favorite subjects – making what you already have do more with zero expenses.

OK, so that was a blatant attempt to get you to click the “Continue Reading” link. It worked and I’m glad you are here. Today’s topic is pretty dry and applicable to a very small Mercedes-driving population so pardon my click bait tactics. While the DIY itself is probably not relevant, I hope you’ll enjoy watching me hack my wife’s Benz to pieces and then see if I can put it back together.

Also, in the name of full disclosure I should point out that our 2003 Mercedes-Benz C320 has 125,000 miles on it and is worth around $6,000 which makes these DIY adventures a lot more palatable. The car did cost $45,000 new but that was back in 2002 when it sailed to US from Germany. I sure hope that the original owner thought it was worth it! We bought this car in 2010 for a much more reasonable $8,000.

Despite all the little annoying things that I had to fix I gotta say that this is one of the best cars I’ve owned. It is literally night and day difference from the 2001 Corolla that it replaced. Not a fair comparison, I understand, but really, a used Corolla will easily set you back $8,000. In fact, we went from a 2001 Corolla with 135K miles to a 2003 C-class with 80K miles for less than $4,000 cash out-of-pocket. Of course the operating costs are a bit higher since we are talking about a luxury German-engineered 6 cylinder sedan with all the electronic gizmos vs. a 4 cylinder econobox meant to be basic transportation. If I had to service a high-mileage Benz at the dealer I would be broke! Can you say TWELVE spark plugs in a 6 cylinder engine?! Luckily, I learned to DIY most of the maintenance and repairs and figured out how to get best deals on parts, so my expenses are not all that much higher.

Since our other car is a two door Mini Cooper our go-to vehicle for family trips is the Benz. I LOVE the way it drives and the usual 6 hour drive to see our relatives does not feel that bad. In the Corolla it was torture. The seats sucked, the car was loud inside and felt underpowered. The Benz is a tank in comparison and I feel spoiled rotten every time I’m behind the wheel. I drive the MINI 95% of the time and it feels a lot more like the Corolla compared to the Mercedes. But at least the Mini is FUN to drive, with good seats (heated!) and a proper 6 speed manual to wring all the performance out of the small engine.

One thing we really enjoy doing in the winter is skiing. For a while there we’d take the Mini Cooper, fold the rear seats down and there’d be plenty of room for the skis and all the gear for the two of us. This year we booked a house on AirBnB to go skiing with the whole family including our son, my sister, her husband and her kids (want a $25 AirBnB credit?). The 3 of us will be taking the Benz loaded up for a week, including Christmas presents and ski gear. One problem – the Benz does not have a fold-down rear seat nor does it have a ski pass.

My initial thought was to get a roof ski rack. However, you’re talking hundreds of dollars since you have to buy a Mercedes-specific base roof rack first and then add a special mount to hold the skis. A pricey proposition to accommodate something that we do just a couple of times per year. There is also a MPG penalty to consider due to additional drag with all the gear mounted on the roof. Nevermind the pain of installing and uninstalling the entire roof rack system every time we wanted to use it and then having to store it all somewhere in between. My frugal senses were being assaulted on all fronts and I didn’t like it one bit.

I thought to myself – why didn’t someone think of making a universal ski rack that could attach to any car and was easy to take on and off? Maybe use magnets at the base, similar to what those pizza delivery guys do to temporarily mount a rooftop sign on their personal cars. At this point I actually thought I might have a good business idea but as with most of my “inventions” someone came up with that long before me.  A quick search revealed that a product like this already existed.


I seriously considered buying this cool magnet ski rack until I remembered that I’ve had the exact same dilemma before and managed to solve it with an elegant $0 cost solution. My old BMW 3-series had the same issue – no folding rear seats. Those Germans will nickel and dime you for every option and a split-folding seat was an expensive add-on. For example, you’d have to fork over $475 back in 2003 to get folding seats in your BMW. A lot of people were already stretching to buy a brand new bimmer and chose to save some money by nixing that feature. As I was buying used I had to work with what was on the pre-owned market – hence no folding seats or ski pass-through for me.

The solution was elegant in theory but did require some power tools and auto mutilation. All BMW’s had a folding elbow rest built into the rear seat. If you got the folding seat option there was a ski bag built into the seat back and a pass-through to the trunk. If you didn’t, there was a metal plate welded where a ski pass-through should be. A well-known hack in the BMW online community called for cutting through the metal plate using a Dremel following the outline conveniently etched into the plate by the BMW at the factory. After cutting through and trimming the opening with some rubber gaskets to make it look more factory and less ghetto-like I had myself a ski-pass spending exactly $0.

I searched online for a similar ski pass-through hack for my Mercedes-Benz C-class (known as W203). I did find one DIY that said that it was possible but without seeing the detailed pictures first I was hesitant to start ripping apart my wife’s car. As our ski vacation was getting closer I said the hell with it and decided to give it a try.

What you see below is a step-by-step DIY on how to modify your C-Class Mercedes-Benz without the factory ski pass-through option to have one that will look good while spending absolutely nothing assuming you have a few basic tools. While it took me a couple of hours to figure out how to do this while taking pictures, it should take you under an hour.

First lets gather all the tools needed to get the job done:


Nothing fancy here. You should already own a decent socket set – you’ll need 10, 13 and 16 mm sockets. Same with a torx bit set (AKA star bit set) – you’ll need T45 and T15 sockets. A box cutter with a sharp new blade is a must have. An X-Acto knife is nice but not absolutely necessary. You’ll also need a flat head screwdriver. And finally, a couple of auto trim removal tools are nice to have so you can remove factory installed clips that tend to break if you use pliers and screwdrivers instead. If you want to check out my recommended set of tools for any DIY auto mechanic check out this comprehensive list.

We are ready to begin. Get in the back and take off the 4 plastic covers that hide the bolts holding the bottom seat cushion. You should be able to pop them off by hand or use a small screwdriver to pry from the bottom. Then take the nuts off the bolts.


You can now take the bottom seat off and out of the car. If you have a kid be prepared to find all kinds of interesting stuff under there. Apparently my son has been stashing his Cheerios down there. This is a great time to pause this DIY and run back inside to get a vacuum.


Look under the back rest cushion and you will find 4 more nuts to remove.


Open the trunk and look for two black plastic covers on the wall separating the trunk from the passenger compartment. Pop both of them out with a flat head screwdriver.


Now you have access to the back seat release mechanism. Stick a flat head screwdriver there and release the catch.


Back in the car, route the seat belts away from the seat back and then push the seat back forward as shown below. You don’t have to remove it from the vehicle. Use your trim removal tool to pop off the 3 clips that hold the seat back cover. You can try using a flat head screwdriver and a pair of pliers but those clips will probably break on you. Right tools make all the difference!


Pull the top of the felt seat back cover to expose the metal seat back. Leave the bottom connected as shown for now. If it comes out just slide the bottom back in. Remove the torx screws holding the plastic cover to the metal seat back.


Now the hardest part – you’ll need to remove the plastic cover shown below. I couldn’t find an easy way to do it and there were a couple of times I thought I will break it while pulling and pushing it out. I was able to get it out from the front of the seat back pulling it over the elbow rest. In other words, all the pulling work was done while squatting on the floor behind the driver seat looking at the seat back as shown below.


With the plastic cover out, push the seat back forward again and put the felt seat back cover back in place but without putting the two plastic clips back. Now take a marker and draw an outline of the hole tracing the metal opening where the plastic cover used to be. After that’s done, take the felt seat back cover out of the car and prepare to cut it up.


After carefully cutting an outline with an X-Acto knife I finished the job with a plain old box cutter with a new sharp blade. You will now have this modified seat back cover. Don’t throw out the felt piece you just cut out!


Now all that’s left to do is put everything back together reversing the steps.

Time for a test ski fitting… Two pairs fit side by side:


How it looks from the trunk:


And from the cabin again with a child seat installed – plenty of room for another child seat 😉


When we return from the slopes and the skis are wet, I usually put a big plastic garbage back over the skis to prevent any dripping. A big towel or a blanket works great too.

A nice thing about this hack is that it’s completely hidden for the most part. When you are not using the ski pass-through you can fold up the arm rest to hide the hole. You can also pop back the felt piece that you cut out. It will hold without any tape and no one will ever know that there is a hole behind it. Here is a picture of the dirty trunk with the felt piece back in place:


We are now all set for our family ski trip and I didn’t have to spend any money, at least not on modifying the vehicle. I’m also happy that we’ll be able to drive up fully loaded for a week-long vacation while still getting a respectable 30 MPG on a highway. All of a sudden this luxo Benz gained a good deal of utility with its newly found ski hauling abilities and potential Home Depot lumber runs. Another DIY and another win for the books!

2 thoughts on “Hacking a $45K Mercedes-Benz in the Name of Utility

  1. Nice! I wonder if we could do this with Mr PoP’s parents’ Lexus! Their 1998 Lexus had a fold down pass through, but the 2006 model they exchanged it for recently looks like it should but it doesn’t. This would be a great hack for the occasional piece of lumber that Mr PoP’s dad needs to pick up when his truck is back at their other house (a good 22 hour drive away!).

    • I’d look up the model/year to see if Lexus offered an optional ski pass-through and if they did, then chances are you can DIY a retrofit similar to what I’ve done on the bimmer and the Benz. I’ve used that pass-through plenty of times on my 3-series…It definitely makes a big difference in utility despite such a seemingly minor feature.

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