Modifications are often a pitfall for those trying to financially justify them. They can be expensive, yet they generally don’t add value. That $5,000 sound system install might actually lower the value of the car because prospective buyers are scared of taking on someone else’s wiring project, aftermarket wheels and tires usually don’t make a car more valuable than one on original rollers, and custom paint is often a love-it-or-leave-it proposition. This Mercedes-Benz CLK 63 AMG Black Series, however, has been modified in a way that seriously increased its value, and the engine’s still essentially bone-stock.
Of course, it helps that we’re looking at a car that’s already rare and coveted. With serious suspension tweaks, a 500-horsepower naturally aspirated 6.2-liter M156 V8, and only 500 examples made worldwide, this extra-hardcore AMG is a legend in its class. However, it seems to suffer a bit from the fact that automatic transmissions of the 2000s weren’t always great.


The seven-speed transmission equipped in all examples was reasonably quick for its time, but it has nothing on a newer torque converter automatic transmission or a DCT. So why not rip it out? Yep, this CLK 63 AMG Black Series has been made even more special by the addition of something it was never offered with from the factory: A six-speed manual transmission.

This swap is the work of Kwiek Classics, a Nashville-based shop specializing in monster Mercedes-Benzes. Builds like transplanting the supercharged 5.4-liter V8 from an S55 AMG into a classic 280SE, then backing that engine up with a manual transmission. Naturally, the next step was to figure out how to pair the awesome 6.2-liter M156 V8 with a row-your-own gearbox, and Kwiek Classics has landed on a solution using a beefier version of Mercedes-Benz’s 716 six-speed manual transmission than the Crossfire unit commonly swapped int older models.
The result is a bit of a monster. OTS and Company, the dealer selling this CLK 63 AMG Black Series, put another manual-swapped example on track against a stock automatic car with racing driver Randy Pobst at the wheel, and there was a real performance improvement around Atlanta Motorsports Park. You can hear the recalcitrance of the automatic transmission in this video compared to the driver-commanded operation of the manual, and that’s reflected in a lap time 1.6 seconds quicker for the manual-swapped car.

So, back to this particular manual-swapped CLK 63 AMG Black Series. It has a little scuffing on the front lip, it doesn’t appear to have had its head bolts replaced, and Kwiek Classics is still working on getting stability control fully functional with the manual swap, but none of those things seem to be a deal-breaker at all. This 28,000-mile example just sold on Bring A Trailer for a whopping $138,000.

For context, here’s a comparable stock CLK 63 AMG Black Series that sold on Bring A Trailer for $86,500 late last year. With 23,000 miles on the clock, it had seen less of the road than the manual-swapped example, and although it’s had a little bit of paintwork on the front bumper, likely to correct stone chips, it does have a clean Carfax. It’s right on the money for where the market is right now, and yet the manual-swapped car pulled a premium of more than $50,000. How wild is that?

This stick-shift-swapped CLK 63 AMG Black Series is evidence that major modifications can increase value if they make a significant and desirable difference to the driving experience. We’ve seen this before with single-clutch automated manual transmission-equipped Ferraris and Lamborghinis converted to H-pattern manual operation with a clutch pedal, but it’s neat to know that the same principle can extend beyond the ultra-expensive world of Murcielagos and 599 GTBs and into slightly more reasonable modern collector cars.
Top graphic image: Bring A Trailer
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Some cars need this. My desire for certain cars would go through the roof with a manual. Specifically… R35 GT-R, Alfa 4C, and the C8.
I understand the desire to do this. Sometimes a car can be perfect except for one component… I love everything about the 8c, but am not in love with the paddle-shift… it’s OK for that generation, but it’s not as great as a quality row-your-own would be. For a superb GT car, she deserved a great manual transmission. DK is working on one (planned to be fully reversible) and I hope it’s fantastic and reasonable to have done.
I wouldn’t just chalk the value up to the manual conversion.
There is a massive spread on CLK63 Blacks. Anywhere from $50 – $200K. Garage bubble examples being the obvious thing, there’s a lot of things to sway the value. It might be a $15-20K bump. It’s certainly not $50K. The fact OTS is selling it certainly helped, as they have some reputation. Granted, the swap itself wasn’t free. This might be a small net bump. It at least recovered its cost, which mods almost never do.
C63 Blacks are in a similar boat, where they tend to swing between high $70s for the worst ones, to better part of $180 for the best examples, with 800 total made.
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M156 manual swaps are very much a thing, and Kwiek isn’t the only one doing them, though I’m aware he’s supposedly got the control weighting absolutely dialed in compared to everyone else doing them right now. He’s the benchmark.
The electronics are the big thing. ABS isn’t something most want to eschew, and stability control is still very much a nice to have. I’m looking at the realities of OEM-level electronic systems integration for another project, and it’s what might take that project to nearly 6-digits — the parts themselves are a third of that. The bulk of the cost is basically OEM-level firmware development and integration. Granted, that’s a much more modern car, and far more complex than these Mercs, with super-unfun encryption on top.
Once electronics get sorted out, we’ll see more of these being done. The demand is there. Heck, I just grabbed a C63 Edition 507 (that I’ve just started remediating) knowing that in time someone will have made the electronics a turnkey solution. I’ve driven other M156 manual swaps to know how greatly they can vary in terms of feel and engagement, but it’s something I’ll consider when the end result is truly great.
Even if you could somehow measure if this specific mod added value, you can rest assured it’s only because it was done with new OEM parts by a well known specialty shop. In short, there is no way I’ll believe the value added was worth the cost for the owner, at least from a purely financial perspective.
As a rule, modify cars because you want the result and consider the money spent to be burned and gone forever.
I never said mods add value. They never do. Trust me when the seller of my C63 just learned that. All of my remediation right now is returning the car to its stock appearance. Especially since the installer of some of the cosmetic modifications did real damage in the process.
It’s exactly why people don’t want modded cars. They’re ever rarely done right, and even if no parts are involved, there’s cost to return to stock.
I went with it because I was willing to spend my labor to save $15-20K.
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I said that SOME mods can RECOVER value, but as you stated, if (big if) this case was one of them because it was done right, by the right shop.
We agree on the exception.
I used to love modding and tuning cars. Until one day at the grocery store i saw a PERFECT.. and i mean Perfect Showroom new Chrysler New Yorker. And then i understood the idea behind keeping things perfect as they were. Now I go out of my way to keep my cars factory, to say nothing of the resale value I just really enjoy riding in time capsules.
I feel you on that. With kids and CA smog, it’s just not worth tuning a car.
I think the main thing about modifying a car is you need a clear GOAL. Don’t just buy and install and ‘upgrade’ for the sake of it. Think of where you want your car to be when it’s finished. Also consider if “finishing’ the project is even obtainable. If you can’t finish the project or accomplish your goal financially or practically don’t even start.
I’m installing a lift on my prius, mainly because the roads in my area are crap and im tired of scraping the chin everywhere. Lift kit, new shocks, rear sway bar, taller tires done for under 2 grand easy to do and that’s all it would take. most people wouldn’t even notice it if I did not point it out or there wasn’t another same model Prius next to it.
Here I was expecting a Tavarish video and instead I get proper engineering and repairs. Love to see it!
For anyone else curious about more on this car and the process, Jason Camissa has a couple episodes of the Carmudgeon Show Podcast on this car with Derek, one of the owners of the dealer that has this car. Part of what’s somewhat glossed over here is that every single component in this transmission swap except for the clutch is an OEM Mercedes part, and it all just works and bolted in exactly. Seriously, the trans bolts up, the clutch pedal, cylinders, lines, shifter, driveshaft, even pressure plate IIRC is all an off-the-shelf direct-from-Mercedes part.
The stability control and the like is down to the ECU not being set up for this since the M156 AMG engine was never paired with a manual. This is conversion is the single closest to stock any manual conversion could be for any car that was never offered with a stick from the factory. It’s a true feat, and from what has been said about the OEM automatic in these, the stick is a massive upgrade.
I wonder about he stability control issue is more of a ‘liability’ thing maybe it could be enabled but the shop doing the work did not want to assume any risk?
I think we’re officially at the inflection point where “Manual nostalgia” is taking over just a little bit. In 20 years the pendulum will swing a bit, and we’ll have more manuals coming off the factory floors. And people will say things like “Remember the Manual Bubble of the late 2020s, that was a crazy time!”
I still maintain my best mod was an antenna delete from the rear quarter panel. That’s at least 5whp from the improved aero. Definitely worth a few grand when I sell someday.
It’s the currated collection of stickers I’ve added that are going to make bank for me.
I think I will buy a mid grade Charger as an investment. But only if it has the factory splitter guards. It’s gonna be worth big money someday!
If you want to keep the splitter guards mint, be sure to apply some protective tape or something. You wouldn’t want those bumper protectors to get damaged or anything.
That, my friend, was the perfect response. I an having a hard time typing due to laughing so hard.
Or, he could set them aside in order to sell his ‘mint’ splitter guards on eBay in a few years for $500.
$700 if they’re pink.
And then you’ll also get the fingers-off-the-steering-wheel wave from the other owners with tape on their splitter guards. They know.