Built between 2003 and 2009, the Mercedes SLR McLaren was a modern-day tribute to the 1950s 300 SLR. The super Gran tourer preceded AMG’s SLS and GT models, both inspired by the 300 SL. Throughout its production cycle, there were some limited edition versions, such as the 722 Edition. There was also a race-prepped version of that, which you could buy. There is, however, a much rarer version of the Mercedes SLR McLaren, which was presented in a “Seen through Glass” video. It was developed by MSO (McLaren Special Operations) and now, one of the 25 made is for sale.

This was actually the swan song of the SLR McLaren before it went away for good. At the time, Mercedes owned 40 percent of McLaren and the British supercar manufacturer was key in developing a proper Mercedes supercar. As the two companies parted ways, McLaren Special Operations decided to give the SLR a proper send-off.

The people at MSO have fitted a more aerodynamic body kit, including new front and rear bumpers, diffuser, hood, and a different grille. There’s also a titanium exhaust system and wheels, exclusive to the MSO.

Performance-wise, the MSO SLR has upgraded steering and suspension. Improved stopping power comes in the form of carbon-ceramic brakes. The MSO treatment has increased downforce by 20 percent while reducing weight by 110 pounds (50 kg). At least some of the 25 cars had an engine tune, which according to some makes it more powerful than the SLR 722 Edition’s 641-horsepower figure. This should mean a 0 to 60 mph (97 km/h) time of under 3.6 seconds and a top speed of over 209 mph (336 km/h).

Mercedes SLR McLaren by MSO specifications

This particular example is listed in Germany and is number 12 out of 25 MSO SLR McLarens. The asking price is €2,600,000 or $3.1 million, which is more than a Bugatti Chiron. If you had bought one new in 2009, it would have cost you $205,615. That’s roughly 15 times appreciation. The SLR McLaren MSO Edition is, arguably, much more obscure and bespoke, but is it worth going for it, instead of a much newer, much faster Bugatti Chiron?