We’ve been obsessively following BMW on social media to keep you up to speed about the return of an icon. In just a few short hours from now, the third-ever CSL will break cover as a rear-wheel-drive M4 Competition with upgrades across the board. The last teaser reconfirms the Coupe Sport Lightweight had to endure a strict diet to shave off what M officials have strongly suggested will be a weight loss of around 100 kilograms (220 pounds).

The hood with its red accents has exposed carbon fiber surfaces, which leads us to believe the entire bonnet is made from the same lightweight material. You can’t have one on the M4 Competition where the aluminum hood is the only way to go. Logic tells us the roof will also be of the carbon fiber variety since it’s standard equipment on the G82.

Speaking of carbon fiber, a previous teaser revealed body-hugging seats with a “CSL” logo illuminated in red, exposed rivets, and a lot of carbon fiber. We also saw the same material being used for some of the aerodynamic bits, which will all contribute to a leaner and meaner track-focused machine. Ditching the rear seats is part of the diet, as will be carbon side mirrors and bespoke wheels with ceramic brakes.

Multiple spy shots have revealed a rear spoiler built into the trunk lid as a visual nod to the M3 CSL (E46) and likely enabling some real benefits in terms of extra downforce at the back. Inside, logic tells us the M4 CSL will be a tad louder than the Competition by removing some of the sound insulation to achieve the targeted weight loss. A manual gearbox would’ve been, but I guess we can’t have it all.

A follow-up to the M4 GTS from 2016, the new CSL will be officially unveiled later today and is believed to be capped at just 1,000 cars.

Source: BMW M / Instagram