Jaguar's flagship series of full-size sedans appears in new designs of lightweight aluminum. Enormous presses at Jaguar's Castle Bromwich body assembly plant in Birmingham, England, stamp out one-piece aluminum bodyside panels stretching from tip to tail, as well as other components including frame and cross brace supports, roof, hood and decklid. All come together to forge a rigid and lightweight structure.

The package size grows considerably in all dimensions. It's longer, wider and taller than the predecessor with more cabin and trunk space. Anyone familiar with the shape of the previous XJ8 will recognize the curvy new version as a bold-faced Jaguar with the signature prow cut by pairs of oval articulated headlamps flanking a twin-port grille, smooth lines sweeping rearward across a long hood and low roof, and a rounded boat-tail back. Yet the rump varies from tradition by nixing a sagging tail for a trunk with less slope to the deck.

Jaguar delivers three XJ variations to North America. XJ8 is the primary model but a dressy version restores the marque of Vanden Plas to the line and a performance edition with supercharged boost wears the badge of XJR. Powertrains come from Jaguar's dual-cam 4.2-liter V8 engine with all torque translated through a ZF six-speed electronic automatic transmission. The transmission shift lever, set with Jaguar's venerable J-pattern gate for automatic and manual shifts, isolates various gear positions so you may shift it yourself without clutching, if desired.

XJ8 and Vanden Plas stock the naturally aspirated V8, which delivers as much as 294 hp. XJR the performance model adds an Eaton Roots blower to the V8 as well as dual air-to-water inter-coolers. As a result, it gushes to 390 hp. Variable-assist power rack and pinion steering and four-wheel disc brakes with computerized anti-lock controls (ABS) and electronic brake distribution (EBD) improve motion maneuvers for all models. A dynamic stability controller (DSC) is also in place, along with an air suspension and Jaguar's computer active technology suspension (CATS).

XJR goes further by adding Brembo disc brakes and 19-inch alloy wheels crowned with Pirelli P-Zero Rosso tires, plus xenon high intensity discharge (HID) headlamps.

Standard cabin appointments for all include leather upholstery and walnut wood trim, adjustable pedals with memory settings also governing driver's seat, steering wheel and mirrors, a rear park distance control monitor, power moonroof and a new electronic parking brake in place of the traditional handbrake lever. Vanden Plas gets even more, like soft-grain leather, heated seats, a power sunblind, 16-way power for front seats and an Alpine audio system with six-disc CD deck.

An optional LCD screen in the dash has a touch screen for controlling climate, audio and optional navigation system or cellular telephone. Further, a DVD-based entertainment system for rear riders uses dual video screens mounted in headrests over the front seats.

Read our Review: Jaguar XJ8

Jaguar's midsize series of rear-wheel-drive (RWD) sports luxury sedans include S-Type 3.0 V6, rated for 235 hp, and S-Type 4.2 V8 with normal aspiration worth 294 hp and the performance-geared S-Type R with supercharging zipping strength to 390 hp. Jaguar puts the ZF six-speed automatic in all three versions, but a five-speed manual from Germany's Getrag is available on S-Type 3.0 by special order.

The sleek shell of S-Type sedans reveals characteristic hints of classic Jaguar lines from past models. A bowed profile with roofline slinking to a low tail evokes images of the popular Mark 2 saloon car from the 1950s, while twin bulges over headlamps as defined in a sensuous sweep rearward across a long sloping hoodline may also be found more recently in past and current editions of Jaguar's XJ sedans.

And that unique prow with pairs of oval articulated headlamps flanking an unusual grille wrapped in chrome: It may bear the DNA of a Jaguar but looks aggressive and provocative.

The S-Type R goes further by adding a bright-finish mesh inset in the grille as rimmed in the body color. Also, there are xenon HID headlamps on tap, plus a spoiler on the tail for high-speed stability. S-Type R adds electronic controls that automatically vary suspension shock damping from soft to firm in order to maximize rider comfort, handling and control.

The sensuous two-door personal luxury cars of Jaguar resurrect styling cues from the fabled 1960s two-seat icon - XK-E - thanks to that extended hoodline and aerodynamic prow. Only change between coupe and convertible occurs with the latter's retractable lid, fully lined with a glass rear window.

The cockpit for all XK models has seats for four. Legroom is sparse in the rear but up front the buckets are clad in rich Connolly leather and adjust with power controls featuring memory settings. Slabs of hand-finished hardwood veneers -- either walnut or bird's-eye maple -- trim dash and console, while classic analog gauges mark the instrument panel.

XK cars gained new powertrains last year and return for 2004 adding an elite XKR Portfolio model with production strictly limited in numbers. Jaguar's 4.2-liter V8 and the ZF six-speed automatic work in all versions. The naturally-aspirated plant slips into XK8 coupe and convertible, worth 294 hp. The supercharged version goes to racy XKR, making 390 hp. External visual clues distinguish XKR -- a wire-mesh grille, functional hood louvers and a spoiler on the rear deck.

Equipment exclusive to XKR includes xenon HID headlamps, a DVD-based navigation system and seats in perforated leather, along with Brembo brakes and aluminum four-piston calipers tinted to silver and revealing the R Performance marque. DSC stability equipment also works on all versions, as does emergency brake assist (EBA).