For as long as Jaguar has been in business, it has built long, lithe and refined machines (much like its legendary hood ornament) for the well-heeled and stately. But for the last few years, the British carmaker’s design studio has supplanted its rather tame, catlike creations with more ferocious, teeth-baring, aggressive-looking machines.

The transformation started with the 2007 XK sports car and then the 2009 XF midrange sedan. Now, Jag’s designers have instilled that killer instinct into the company’s legendary flagship sedan, the XJ . Its redesign is radically different from its predecessors, which have all shared the same basic shape since 1968, but it's certainly turning heads and creating notice.  The old car’s proportions were like nothing else still on the road; it appeared as long and regal as its bloodline. While the new XJ shares some of the same DNA, this is not your old man’s saloon, as you can see by this XJ.

The hallmark of the new design is a long, flowing roof line, a feature, we fear, that might alienate traditionalists. With its rakish rear window and side glass framed by a bold chrome parabola, the look is striking, though it is in keeping with coupelike 4-door cars like the Mercedes CLS. Not that the new car is without references to earlier models, but they are subtle, at best.

Yesterday, we had a chance to sit down with Giles Taylor (pictured, man on right), senior design manager at the Jaguar Design Studio and the man mostly responsible for the new XJ, at the XJ’s New York City debut to discuss the cat’s latest saloon and how Jag aficionados might perceive it. Read on to see what he had to say.

MSN AUTOS: Well, the new XJ definitely doesn’t look like any XJ we’ve ever seen. And you can definitely see the XF design language in this posh feline. Plus, we know that it’s only 21 mm longer than the previous XJ, but somehow it seems much longer and leaner. How did you do that, with a little visual trickery?

TAYLOR: Yes, very much so. Our primary design vision was to get this lovely sense of sleekness that would differentiate the XJ from its competitive set, even though we had to keep headroom, elbow room, boot literage, et cetera, very competitive so we could compete. The real spirit of the car had to have this sort of length. We wanted a full 5-passenger car, so we’ve moved the profile of the roofline rearward. The window graphic really pulls the eye to the rear of the rear wheels. The roof line takes the volume, the proportion of the car right to the tip of the car. And the rear fender gives the car the appearance that it’s being pulled to its extremities, fore and aft. It gives the car its incredible sleekness. In addition, darkening the rearmost roof pillar reduced its visual weight.

MSN AUTOS: During the presentation, you said that this design was a clear departure from past XJs, yet still pays homage to the lineage. This seems like a contradiction in terms. What car most influenced the lean and long demeanor of the new XJ, and how?

TAYLOR: The car I would pick out would be the original XJ6 from 1968. It had this lovely low fuselage and slim glass canopy; as a result of that, your eye stayed low. If you start off with a very fine superstructure, your eye stays on the mass down low. I think that certainly a quality of the new model. Your eye stays low, and you read the linear length of that mass subliminally. It’s something best appreciated when the car is moving past you on the street. The blackout wrap-around rear glass also knocks off a lot of the car's mass.

MSN AUTOS: I rather like the rear end of this car -- much more dramatic than the XF.

TAYLOR: The front screen is about the same rake as the XF. But, yes, the rear is much different. You get this sort of lovely tail off the rear quarter as it sort of comes off the B-post and over the rear. There is a great sense of elegance derived from that.

MSN AUTOS: And the taillights are radically different, too.

TAYLOR: Yeah, they look great at night. We are the only car out there to have a top surface light. So when the car rolls up you get this quite elegant piece of jewelry to highlight the rear portion of the car. We refer to them as cathedral window lamps.

MSN AUTOS: But how are you justifying this more youthful, aggressive look to more traditionalist XJ enthusiasts? Or are you looking to draw a new generation of Jag fans?

TAYLOR: I think we can bring them with us into the modern age. Yes, the exterior is different. But I think inside we are offering them a whole lot more than what they currently have in terms of richness of materials and quality and craftsmanship of materials. The exterior, the philosophy of the car as a whole still adheres to "grace, space and pace," which are the underpinning values of any Jaguar post-WWII set forth by Sir William Lyons [Editor's note: Sir Lyons is the company’s legendary founder]. I think you get the grace, the space, the now more velocity. It’s a very handsome car, has a quality of comportment. It infers a certain level of exclusivity. I also think, especially the front end has that level of confidence and stateliness to bring traditional XJ owners with us. We definitely are not trying to leave them behind. But we had to modernize and move forward.

MSN AUTOS: Not a bad job.