Less than one month out from their spectacular auction during Monterey Car Week, RM Sotheby's continues to announce rare and exciting vehicles that will go under the hammer at Pebble Beach. The most recently announced jewel up for grabs is a 1994 McLaren F1 "LM-Specification" which is expected to fetch $21 million to $23 million this August.

In addition to the six track-only F1 LMs of the same name, a pair of road-going F1 LM-Specification cars were built to honor the F1 GTRs that gave McLaren its first 24 Hours of Le Mans win in 1995. To achieve the same specification as the half-dozen track-ready F1s, McLaren took a normal street-legal example and dropped in the GTR's unconstrained 6.1-liter V12, which was good for 680 horsepower compared to the regular F1's paltry 618. In addition, the F1 LM-spec gets an Extra-High Downforce Kit in the form of a large rear wing and vents on the front fenders, plus centerlock 18-inch wheels from the F1 GTR. Aside from being drivable on more than just racing tarmac, the F1 LM-spec's main advantage is that it retains the F1's full interior rather than the track F1 LM's stripped-out cockpit, so you can still squeeze three people inside for a Sunday drive.

This F1 LM-spec, chassis number 018, is the first of two F1s converted to LM-spec in the world, the second of which was sold last year as part of RM Sotheby's new private sales program. Before its LM transformation, this 1994 F1 was finished in Midnight Blue Pearl with a black interior. Its second owner decided the ultimate road-going McLaren just wasn't ultimate enough and had it sent back to to the factory for the LM conversion in 1999, where it was also repainted Platinum Silver Metallic and the interior reupholstered in cream leather with beige Alcantara accents. Other modifications included adding an actual radio to the car's CD player, changing out the dampers and springs to race-ready ones, and replacing the steering wheel.