This badge will only go on the most hardcore M models.
A little while ago, we heard rumors that BMW was considering bringing back the CSL (Compact Sport Light) name for new M cars. These rumors seemed have faded into the background after BMW released models like the track-focused M4 GTS and the M4 CS. The M4 GTS was the spiritual successor to the old E46 M3 CLS, but people seemed to be more interested in flipping it for a profit than actually racing it. Now it seems like the CSL rumor could be back on the table after an interview from Road and Track with M car boss Frank Van Meel.
Van Meel said that CSL will replace GTS as the top level M car in a new system that will have four tiers. There will be a base M car, then a competition pack, then a CS and finally a CSL. "CSL [will be] the top-of-the-line track tool, made on the track for the track, just with a number plate," Van Meel said. The CSL will have all of the track goodies such as cup tires, coilover suspension, a roll cage, water injection, and a fire extinguisher. Van Meel clarified that the CS is "also a track tool, but with four seats," and more focus on comfort. This is a bit like AMG used to do with its normal models and the hardcore Black Series cars.
We don't know specifically what models will get the CSL badge, but Van Meel confirmed that there will never be an X5 M CSL. We'd predict that the M2 and M4 would be the most likely candidates for hardcore models, though Van Meel has not ruled out four-door models like the M3 or M5. The 3.0 CSL and the E46 M3 CSL are two of the most legendary cars that BMW has ever built, so we are definitely excited to see this badge make a comeback.