BMW only said that it would debut two concept cars at the 2015 Monterey Car Week in California on August 13 without giving any details, but rumor has it one of them will be a thinly disguised production model.

And not any model, the BMW M4 GTS, which is the badge received by lightweight, track-focused versions of BMW M cars. The last time BMW used the GTS moniker was in 2009, when BMW launched the M3 GTS, built in a limited run of 150 units.

According to a report from Autocar, the BMW M4 GTS pre-production study will take inspiration from the M4 MotoGP safety car.

It will feature only minor styling changes compared to the production model, which is expected to go on sale next summer. The BMW M4 GTS will use a water injection system which will allow the 3.0-liter twin-turbocharged straight six engine to produce 467hp compared to the standard M4’s 425hp. Furthermore, the BMW M4 GTS is likely to be significantly lighter than the standard M4’s 1,572 kg (3,465 lbs).

As for the second concept car to be unveiled at Pebble Beach, it is believed to be an updated version of the 3.0 CSL Hommage study (pictured), first shown at this year’s Concorso d’Eleganza Villa D’Este. It remains to be seen whether BMW has serious plans with the 3.0 CSL Hommage as a limited-run model.

PHOTO GALLERY