The BMW E9 CSL occupies a sacred place in the brand’s history. Lightweight, elegant, and instantly recognizable thanks to its dramatic “Batmobile” aero package, it remains one of Munich’s most celebrated performance cars. Yet for all its motorsport pedigree, the original CSL never enjoyed the kind of power modern enthusiasts crave.
That’s where this remarkable one-off creation comes in.
Built roughly a decade ago by German workshop MKO, founded by BMW enthusiast Michael Oberhauser, this machine answers a question nobody at BMW ever officially dared ask: What if an E9 CSL had been developed using the heart and soul of an E39 M5?
The answer is sitting before us in steel, aluminum, and hand-crafted ingenuity.
Rather than performing a simple engine swap, MKO essentially merged two generations of BMW performance legends into a single cohesive package. The project reportedly began with an E39 M5 and components sourced from two E9 CS coupes. What followed was a painstaking transformation that blended 1970s styling with the engineering of one of BMW’s greatest modern sports sedans.
The surgery went far beyond cosmetic alterations. According to details from the original build story, the upper structure of the M5 was removed, the wheelbase shortened by nearly eight inches, and an E9 roof grafted onto the modified chassis. The goal wasn’t simply to recreate the look of a classic coupe—it was to preserve its delicate proportions while retaining the mechanical sophistication underneath.
Achieving that balance required extensive bodywork. The front fenders were widened by roughly 2.5 inches, while the rear arches gained around four inches of additional width. Much of the custom fabrication was completed in Romania, where craftsmen hand-formed bespoke body panels to create a seamless blend of old and new.
The finished product looks as though BMW’s skunkworks division secretly built a restomod decades before the term became fashionable.
Visual cues pay tribute to the legendary 3.0 CSL “Batmobile,” including a roof-mounted spoiler, small front-fender aero fins, classic Hella driving lamps, and period-inspired badging. The body wears Porsche-sourced paint and now rides on 19-inch Alpina-style wheels wrapped in sticky Continental SportContact 7 tires. Early versions reportedly wore standard E39 M5 wheels, but the current setup better suits the car’s muscular stance.
Inside, the modern underpinnings become more apparent. A modified E39 M5 dashboard remains in place, accompanied by heated Recaro seats, dual-zone climate control, power windows, and a Pioneer touchscreen infotainment system. It’s an unusual mix of classic grand tourer and modern sports sedan, complete with creative engineering solutions such as relocating the driver’s window switch to the center console.
The real star, however, lives beneath the hood.
Power comes from BMW’s legendary 4.9-liter S62 V8, the naturally aspirated masterpiece that made the E39 M5 a performance benchmark. In this application, the engine has been reworked to produce 432 horsepower, all sent exclusively to the rear wheels through a six-speed manual transmission and a limited-slip differential.
Considering the E9’s significantly smaller dimensions and lower visual mass, the combination borders on outrageous.
Handling upgrades include adjustable KW coilovers and the M5’s braking hardware, giving the car the stopping power and chassis control needed to keep pace with its muscular powertrain. The result is less a restoration than a BMW hot rod—one that combines the analogue charm of the 1970s with the mechanical confidence of one of the greatest M cars ever built.
It’s the sort of machine that could only exist outside BMW’s corporate walls: too expensive, too complicated, and perhaps too niche for production. Yet that’s exactly what makes it so fascinating.
Now, after years of turning heads and challenging conventional BMW history, this singular creation is looking for a new caretaker. Listed through Bring a Trailer Germany, the hand-built CSL-M5 hybrid had attracted bids of €42,225 at the time of writing.
For BMW enthusiasts, that’s a small price for a glimpse into an alternate universe—one where the E9 CSL never stopped evolving.
Source: Autocar
