This impressive Mercedes McLaren SLR Roadster is one of just 25 examples converted to ‘McLaren Edition’ spec by McLaren Special Operations.

Out of those 25, it’s believed that only six of them were Roadsters, which makes this SLR a truly unique supercar. But what exactly is a McLaren Edition SLR?

Not many people remember that once production of the SLR stopped and the collaboration between Mercedes and McLaren ceased to exist, McLaren Special Operations offered the conversion package to owners as a way of boosting the McLaren part of the SLR’s identity.

The example you see here is also the first SLR to receive the ‘McLaren Edition’ treatment from MSO, with a commemorative plaque on the center console bearing the desirable #001 designation.

This stunning SLR is currently offered in an online auction at Collecting Cars, with the odometer showing just 1,696 miles from new. The supercar, which has a single owner since new, started life as a ‘normal’ SLR but eventually went back to MSO for its conversion.

The upgrade package includes a completely redesigned body kit that consists of new bumpers front and rear, new front fenders, bonnet vents, a rear decklid with an integrated wing and a massive diffuser. McLaren claims that the bodywork revisions were designed to increase downforce in addition to making the SLR looking even more aggressive.

Under the skin, the McLaren Edition SLR got an upgraded suspension, a modified steering setup and a custom MSO engine tune in addition to a louder bespoke exhaust system that retains the iconic side-exit pipes. Although an exact figure isn’t mentioned, the thunderous supercharged 5.4-liter V8 engine from AMG is said to be making significantly more power than the 640 HP SLR 722S model.

The interior was also redone in red leather and black suede, with the leather extending to the dashboard and center console. A carbon-fiber steering wheel is also part of the package.

The top bid at the moment of writing for this totally unique Mercedes SLR McLaren is £250,000 (around $320k in current exchange rates) and will likely go for even more, given its one-off MSO-stamped status and the fact that there are still four days left until the auction ends.