With impeccable timing Arden released teaser shots of its AJ21 just as Jaguar XF-R spy shots leaked onto the web.Hooligan looksJochen Arden is renowned for his uncharacteristic passion (being German) for British cars; especially Jaguar. The affluent Krefeld-based businessman offers some very alluring aftermarket modification packages to Jaguar products; the latest XF sedan being no exception.Although the Arden styling package – with its new LED underscored bumper, rear spoiler, grille and side skirts – is hardly a study in effortless aesthetics; the look is as forbidding as those cars (M5, E63) Arden is aiming the AJ21 against.Huge 21-inch mags leave one in no doubt this is a tuning job from a typically German engineering concern – despite its British product base. The XF shape barely survives the exterior design modifications with a semblance of Jaguar elegance in tact. Makes a statement though. Hooligan performance tooJochen Arden never intended to build a charlatan of a car though; performance had to be commensurate to the styling drama. Bored out to 4.5-litres and housing a new crankshaft and connecting rods the supercharged V8 produces 404kW in full-spec AJ21 trim - after plenty of ECU trickery and exhaust modifications have been employed. Obviously the 250km/h speed limiter has been disabled too. Although Arden is understandably mum about performance figures considering the verbal attacks M5 and E63 owners visit upon anyone who dares challenge the superiority of their vehicles, suffice to say the AJ21 should be plenty quick.To ensure powerful and predictable deceleration from high-speed Arden have a set of 390mm discs up front operated by six-pot callipers, and 340mm items at the rear clasped by four-pot callipers. Handling is sharpened with a set of custom Arden springs working in partnership with Blitstein shock absorbers; lowering the AJ21 by 30mm.Perhaps the most endearing part of the AJ21 package – as with all Arden Jaguars – is the Jaguar hood ornament proudly leaping forth on the bonnet, where it should be. Inexplicably absent on the standard XF range though - Tata should take note.