Pleidelsheim’s 30th-anniversary M SEC is already sold out: carbon fiber widebody, blueprinted AMG M156, Öhlins and Brembo. Across the Atlantic in Stuart, Florida, RENNtech is building 12 of the same C126 coupe the other way — with a 7.5-liter V12 and a manual transaxle.
Bruno Sacco’s big Mercedes coupe never needed help looking expensive. The C126 SEC — pillarless, long-hooded, quietly enormous — was the car that made a 1980s boardroom look underdressed. What it did need, four decades on, was a heart that matched the silhouette. On Nov 6, 2026, that answer went public from two workshops at once: Mechatronik in Pleidelsheim, Germany, with a sold-out 30-car M SEC built around AMG’s last great naturally aspirated V8, and RENNtech in Stuart, Florida, with a 12-car V12 program that the U.S. press has already nicknamed the Sledgehammer.
Top Gear has driven the German car. Auto Bild lapped a prototype at Ascari. Mercedes-Fans has the brochure numbers. Together they describe something rarer than another restomod headline: an OEM-plus SEC that still feels like a Mercedes, while a Florida shop across the state line from Miami is building the same coupe as a coachbuilt V12 hammer.
Mechatronik turns 30 in 2027. The M SEC is the birthday present and the third model in its New Tech series: a customer-supplied C126 SEC, stripped to a bare shell, cathodic-dipped against rust, then rebuilt by hand with one employee following each car through the shop. The run is capped at 30 cars. Auto Bild reports every allocation is sold. Mechatronik will not publish the price; only the owners know what they wrote the check for. The buyer also brings the donor coupe — Mechatronik rebuilds it; it does not mint a new VIN the way HWA does with its reborn 190E.
That matters for U.S. and Canadian collectors. Period AMG Widebody 560 SECs have left the bargain bin. A low-mile 1987 example cleared about $720,000 in Miami in December 2022, and Auto Bild says bids on clean originals now run well above €500,000. The M SEC is not trying to be a clone of those cars. It is trying to be the SEC you can actually use — with modern brakes, modern damping and an engine that still sounds like a Mercedes when you start it on a cold morning.
Under the long hood sits AMG’s M156 — the 6,208-cc naturally aspirated V8 the factory badged as a 6.3 out of respect for the old M100. Mechatronik rates it at 500 horsepower at 6,800 rpm and 630 Nm (about 465 pound-feet) at 5,200 rpm. Top Gear’s Tom Ford stresses the important bit: the engine is blueprinted and refreshed, not tuned. Reliability and manners beat dyno screenshots. Drive goes to the rear wheels through AMG’s Speedshift 7G-Tronic seven-speed automatic, with a multi-plate limited-slip differential and a stainless exhaust you can order louder or quieter depending on how neighborly you feel.
Outside, Mechatronik’s carbon fiber kit covers the bumpers, fenders, side skirts, cladding and a slim rear spoiler — a modern take on the 1980s AMG Widebody without the period cars’ uneven arches. Customers can leave the weave exposed, ghost it under tinted clear, or paint everything body color. Headlights are either restored originals or a full LED setup with slim daytime running lights. Wheels are 19-inch either way: a monoblock that nods at the Hammer era, or a machined cross-spoke, both on Michelin Pilot Sport 4S rubber (Cup 2 optional on the sharper pack).
Chassis work is Öhlins Road & Track hardware, dual-flow valved and set up as a fast GT rather than a track toy. Standard Brembos are 360 mm up front and 330 mm at the rear. The optional GT Package loses the rear seats, sheds about 88 kilograms of dry weight (1,624 kg versus 1,712 kg), fits 390 mm front discs, and lifts the electronic limiter from 250 km/h (about 155 mph) to 280 km/h (about 174 mph). Claimed sprints: 4.2 seconds to 100 km/h in standard form, 4.0 seconds with the GT Package.
Ford’s Top Gear verdict is the one that sticks. The M SEC starts with that classic AMG V8 bark, then settles into a muscular woofle. Steering is slower than a modern sports car, but once you commit past the first few degrees the coupe turns in cleanly, with body roll that tells you what the Michelins are doing instead of pretending physics took the day off. It irons out broken pavement, then holds 120 mph on an open autobahn with only a flutter of 1980s aero. The GT Package’s louder exhaust and bucket seats are available; Ford preferred the calmer car — the one that still feels like an SEC with bite, not a race car in a tuxedo.
Inside, the architecture stays C126. You can keep the original electric seats, fit squashy classics, sports-comfort chairs or carbon Recaro shells. Woods, leathers and the headliner are made to order. The big change is a three-gauge cluster with a small round digital display nested in the left pod for gear, mode and trip data. A Blaupunkt-look radio hides USB and Bluetooth behind the tape-deck face, and the optional audio stack runs ten speakers and three subwoofers for a claimed 1,560 watts of whatever you streamed in 1989.
Same coupe. Different religion. In Stuart, Florida — about two hours up the coast from Miami — RENNtech Classics is building 12 C126 SECs around a hand-built 7.5-liter M120 V12. Output is 660 horsepower and 650 pound-feet. The gearbox is a bespoke manual transaxle. Brakes are carbon-ceramic. The widebody is framed as functional — cooling, aero, high-speed stability — not a costume, and every car is a full frame-up restoration personalized at 7825 SW Ellipse Way. First delivery is scheduled for December 2027, allocations first-come, first-served. Price, like Mechatronik’s, stays in the sales office.
The nickname writes itself. CarBuzz and others call it the Sledgehammer — a nod to AMG’s 1980s Hammer, and a reminder that founder Hartmut Feyhl came out of that world before planting RENNtech in Florida in 1989. The M120 is the aluminum V12 that powered the CLK GTR and the Pagani Zonda; RENNtech’s 7.5-liter take is sold as one of the largest naturally aspirated V12s still in active production, with equal-length stainless headers and a note no twin-turbo V8 can fake. Motor1 and CarBuzz have covered the reveal; for now the public images are still official renders, not finished cars in the metal.
AutoNext already put the contrast on the page: Mechatronik leaves the M156 inside AMG’s own power band and aims the car at long roads; RENNtech hands outright power to a 660-horsepower V12. One shop keeps the Mercedes identity and a seven-speed automatic. The other invents the V12 SEC Stuttgart never dared to build, with a stick shift and carbon-ceramics. Both are limited-run cars. Both ask the buyer to wait into 2027 and beyond — AutoNext notes Mechatronik’s hand-built cadence means the 30th M SEC may not land inside the anniversary year, and RENNtech’s first Sledgehammer is dated December 2027.
If you want the SEC that still behaves like a Mercedes on a Sunday drive to the Keys — rear seats optional, automatic gearbox, an AMG V8 that has already proved itself in a decade of E63s and S63s — the M SEC is the cleaner OEM-plus play. The catch is there is no open allocation; you are shopping the secondary market for a deposit or waiting on a canceled build. Ask which M156 serial the car carries and how the early head-bolt issue was handled — neither Mechatronik’s page nor the first-drive stories spell that out.
If you want the loud Florida statement — V12 soundtrack, manual transaxle, carbon-ceramics, a dozen cars worldwide — RENNtech’s Sledgehammer is the booking to make while December 2027 slots are still a conversation. Expect renders until metal shows up, and treat pricing as a private quote. Either way, the C126 SEC is having a second act as a coachbuilt canvas, and U.S. buyers finally have a hometown option parked next to the German one.
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