2007-2014 Shelby Gt-500 Ford Racing Cobra Blue Valve Covers M-6582-c on 2040-parts.com

One Lap of the Web: Cool classic concepts, Rat Pack Cadillacs and even more Vin Diesel

We spend a lot of time on the Internet -- pretty much whenever we're not driving, writing about or working on cars. Since there's more out there than we'd ever be able to cover, here's our daily digest of car stuff on the Web you may not otherwise have heard about. -- Petrolicious brings us an awesome VWvortex forum thread packed with prototype photos, design proposals and concept sketches of everything from the Iso Grifo to the 1994 Mustang.

Meet the new Mercedes-Benz SL400

This is our first photo of the upcoming Mercedes-Benz SL400 luxury roadster, a model that effectively replaces the SL350 as part of a series of subtle changes brought to the SL lineup. The move aims to goose sales of the luxury roadster two years after it first hit showrooms. The SL400 is powered by Mercedes-Benz's twin-turbocharged 3.0-liter V6 direct-injection gasoline engine unveiled in the E400 early last year.

Jaguar F-type R coupe (2013) first official pictures

By Ollie Kew First Official Pictures 20 November 2013 08:00 This is the Jaguar F-type R: a hot cat with a tin (or glass) roof. It’s the stiffest production Jaguar ever, and with the 542bhp supercharged V8 from the XFR-S up front, one of the fastest (and sexiest) too. The F-type R, which has 54bhp more than the F-type V8 S roadster, launches to 62mph in just 4.0sec.