Ever wondered why Merc dubbed that one SLR as “722″? Nope, it’s only with RENNTECH upgrades that the car fully justifies the number with all 722 horses. The designation was simply chosen to pay tribute to Stirling Moss’ 1955 Mille Miglia run. Yup, that’s a cheesy motoring history trivia for you. Anyway, here’s a video showing glimpses of history and the SLR McLaren 722.