[4][5] The X350 was noted for its advanced electrical systems,[6] self-leveling, adaptive air suspension, and full aluminum unibody chassis and bodywork, among the first for a mass-produced automobile.

With an unpainted and highly polished example of its all-alloy body shell on display, the X350 debuted at the 2002 Paris Motor Show.

[14] The X350's aluminium bodyshell used an aerospace construction method, a hybrid of adhesive bonding and rivet joinery and known as rivet-bonding or riv-bonding, which was an industry first in volume automotive production.

[20] To ensure manufacturing feasibility, numerous styling elements required a redesign to accommodate forming in aluminium rather than steel, including the bonnet profiles, especially around the headlamps; the radii in the wing-to-bumper gaps and the rear wing/door shut pressing; the side light configuration, and the bodyside haunch.

[8][2] A hydroformed aluminium extrusion with an energy-absorbing foam cover formed a bumper beam cross-member, to provide strength and crushability in the event of a minor collision.

Sacrificial extruded aluminium crash cans were designed to protect the body structure and front-end componentry.

[2] Steel is used for front and rear subframes, and magnesium, which is as strong as aluminium while 30 per cent lighter, is used for seat frames and lateral instrument panel beams.

Ford retained the bonding and riveting patents of the XJ's aluminium monocoque body when it sold Jaguar to Indian automobile manufacturer Tata Motors in 2008.

[2] From the previous generation, the overall body was wider, longer, and higher—with increased head, leg, shoulder, and cargo room—and carried a .32 coefficient of drag.

[2] Ian Callum, who took over the position of Director of Design after the death of Geoff Lawson, summarised: "The new XJ is a luxury car with a true sense of gravitas.

The proportions, stance and obvious dynamic quality clearly display that all-important Jaguar DNA and give it real presence on the road.

"[9] At introduction, standard equipment included mirror-matched walnut burl wood grain trim throughout the interior, piano-black center console trim, leather seating, wood-trimmed steering wheel, leather-covered overhead assist handles, dual-zone automatic climate control, glass electric tilt and slide sunroof with single-touch open/close, rain-sensing automatic wipers, automatic headlights, front fog lights, 24 lamp LED taillights, front and rear parking sensors, boot power latching mechanism, electrically adjustable steering wheel with memory and entry/exit function, electrochromic self-dimming side mirrors with compass, a trip computer, electrically adjustable pedals with 2.5 inch travel, 4 power points, all window one-touch up/down power operation, metallic paint (no-cost option), a full-size spare tyre, electronically tilt and telescoping steering wheel, keyless entry, puddle lamps, electronic park brake, and 8-speaker, 320-watt sound system with boot-mounted 6-CD changer and in-dash CD player.

[1] Optional equipment included xenon headlights, headlight powerwash, adaptive cruise control, multi-stage heated seats, heated steering wheel, DVD navigation (with postal code programming where country-provided), soft-grain ruched (micro-pleated) leather seats and trim, electrically adjustable pedals, and rear-seat multimedia entertainment system for CD listening or DVD movie watching via front seat head restraint-mounted video screens.

The latter engine's valvetrain had a dual overhead cam design with four valves per cylinder and its top speed was electronically limited to 155 mph (249 km/h).

This became an option in 2004 when a long-wheelbase configuration was introduced, along with the supercharged variation of the XJ8 with the more luxurious Vanden Plas or Daimler interior.

A distinctive wire mesh grille and chrome-finished side mirrors set the Super V8 and the XJR apart from the less expensive XJ saloons.

The Daimler Super Eight was essentially the same car but had a different grille, boxwood inlays finished in wood veneer, and several other interior luxuries as standard.

Previous and successive versions of the XJ were also used by Margaret Thatcher, John Major, David Cameron, Theresa May, and Boris Johnson as their Prime Ministerial Car.

"[38] Despite its similarity to the XJ (X308), the X350 was praised for its elegant styling, engine, technology, interior, and handling, while the rear legroom was relatively small considered the car's length.

In his review of the 2003 Jaguar XJ8, Jonathan Hawley wrote: "When pushed hard over lumpy and twisting roads, the air suspension can get a little confused and produces some nasty thumping noises.

The big Jag still delivers a luxurious ride, though its aggressive wheel/tyre package makes you aware of the road surface to a greater extent than previous models.

Criticism rested on the rear legroom despite improvement and the lack of a full manual control of the automatic gearbox.

Burgess concluded: "The big advantage that this Jaguar offers over and above the Audi A8, BMW 7 Series and Mercedes–Benz S–Class is a sense of individuality.

While the Germans are caught in a technological spiral of ever–outdoing each other, the British car gets on with the job of looking after the driver and passenger is a rather charming way.

The XJs deliver the best EPA fuel mileage ratings in this class, and none carries a Gas Guzzler Tax.

Classic Motoring concluded: "The X350 and the 358 facelift carries on the XJ's tradition by offering not only astonishing value but also a driving experience that few others can match let alone surpass.