- The BMW 858 CSL is a unique restomod-style creation based on the E31 8-Series.
- Key features include a V10 engine swap from the E60 M5, paired with a manual gearbox.
- It also features a reworked carbon fiber body and a completely redesigned interior.
The 8-Series E31 stands out as one of the most visually striking coupes in BMW’s storied history, often fueling the creative fire behind numerous restomod ventures and bespoke builds. Sure, it wasn’t exactly sporty—more a lavish grand tourer flaunting BMW’s penchant for high-tech complexity—but it sure turned heads.
Enter the BMW 858 CSL, a gorgeous one-off build that blends a custom carbon fiber body kit with the beastly thrust of a V10 from the M5, all tied together with a manual gearbox. Crafted by Rein Speed Shop, this unique build made its grand entrance at the Legends of the Autobahn event in Monterey, California.
More: Manhart Makes The E31 BMW 8-Series Great Again With E39 M5 V8 Manual Swap
The project began with a BMW 850i as the donor car, aiming to replace the original V12 with a stroked S85 V10 from the E60 M5, increasing its displacement from 5.0 to 5.8 liters—thus inspiring the car’s designation as the “858 CSL.”
While specifics on the tuned V10’s output remain undisclosed, the original 5.0-liter S85 engine was capable of 507 hp and 520 Nm (384 lb-ft), significantly outperforming the E31’s V12 variants, which ranged from 300 hp in the 850i to 375 hp in the 850 CSi. Notably, the V10 is coupled with a six-speed manual gearbox, channeling power to the rear wheels.
The engine and gearbox combination isn’t the only interesting aspect of the BMW 858 CSL. The grand tourer received a neat looking carbon fiber bodykit designed by independent artist Jonsibal, complemented by a thoroughly updated interior.
The boxy, wide fenders blend seamlessly with the rest of the bodywork and redesigned bumpers, injecting an extra dash of sportiness into the classic lines of the 8-Series. A standout modification is the removal of the E31’s signature pop-up headlights, now replaced by hood vents to channel more air to the V10 engine.
Other cool touches include the clear taillights, new quad tailpipes, and custom-made alloy wheels. The end result is a gorgeous restomod, with references to several BMW products like the Nazca C2 concept and the E46 M3 CSL.
The interior of the E31 has been upgraded with new bucket seats and several components from recent BMW M models, including the E60 M5’s steering wheel, instrument cluster, climate controls, gear knob, and start-stop button. Additionally, the car is equipped with a modern infotainment display and a BMW iDrive toggle on the center tunnel.
Unfortunately for fans of the BMW 858 CSL, Rein Speed Shop created it as a one off. We contacted them for more information and will update this story accordingly when they get back to us.