The L4p RENNtech McLaren Mercedes SLR777 – the world’s fastest SLR – puts its money where its mouth is and set an incredible quarter-mile record of 9.76 seconds @ 140.8 mph. This one of a kind SLR that features a Mansory Renovation body kit, is powered by a RENNtech-tuned V8 with more than 700-hp output. Check out the car’s record breaking run after the jump.