At the $100k price point, a car is increasingly an emotional -- not logical -- purchase. No one really needs a six-figure car, right? (Although many of us desperately want one.) It's vehicular arm candy; something that looks good -- and makes you feel great just because it's yours.

Or should.

The Jaguar XKR is all that -- and more. Its sinuous, aluminum-bodied exterior is as cellulite-free as a Victoria' Secret underwear model -- while its 420 horsepower supercharged V-8 engine defends its turf like a silverback Gorilla, daring challengers to make eye contact. You will be envied behind the wheel of this car.

And that is what makes it worth its $91,835 MSRP (for the convertible; the hardtop coupe's a bit less pricey at $85,835).

The observant will note that Jag has dropped the "8" from the XK-series line -- so as to denote that the '07s (including ultra-performance R versions) are entirely new models. It's a major redesign, not an incremental freshening-up. The '07 XK's exterior and interior cosmetics are completely revised and the car rides on a longer wheelbase -- 108.3 inches vs. 101.9 inches previously. The longer wheelbase makes the "plus two" back seats of this two-plus-two coupe/convertible a bit more capable of being used to carry passengers. Though "legroom" is probably not the right term, there is at least some room for legs back there; not much -- but some. I had my 5-foot-eight wife sit back there (briefly) one night. It's neither easy to get in nor comfortable once you have -- but it is doable (and livable), at least for short trips.

The semi-functional back seats are a small concession to everyday practicality -- but an important one, if having the ability to occasionally (if not so comfortably) carry a third passenger means the difference between an indulgence rationalized -- or a dream unrealized.

The updated bodywork of the new XK has some cues taken from the old XJ220 supercar -- and some might see a little Aston Martin emulation as well (especially the nose cone). It's wide, low and swept back -- with twin flush-mounted air vents on the hood, wire mesh grilles and matte aluminum "character bars" on each fender for the R. Big nineteen-inch rims are standard -- with even bigger 20-inch rims available. High-capacity Brembo brakes (14 inch rotors in front; upgraded from last year's 12-inchers) with powder-coated and embossed calipers provide the expected stopping prowess -- and look nice, too. The use of aluminum for the exterior shell drops the weight of the car by 154 pounds (for the coupe) and 220 pounds for the convertible -- relative to the previous generation XK8. Jaguar says it also makes the car stiffer and thus less susceptible to squeaks and leaks (convertibles) as well as improves chassis dynamics and handling. In fact, only the addition of some extra bracing in the rear was needed, according to the engineers, to upgrade the '07 XK's chassis for R duty -- and the extra 120 horsepower that comes with it.

The inside of the '07 XK is more direct, more focused -- with a simplified central gauge cluster and many of the secondary controls and buttons for things like the audio system and GPS integrated into a single touch-screen "interface" (more on that below). In the R, the cabin is defined by the extensive use of engine-turned metallic trim plates that set the proper mood for what comes next when you fire up the 420 horsepower, 4.2 liter V-8.

The R's supercharged engine is teamed with a six-speed automatic transmission featuring standard and Sport modes accessed via the reverse L-shaped center console shifter -- or use the F1-style paddle shifters on the steering wheel. Either way, 0-60 comes up in under 5 seconds -- with top speed governed to 155 mph. (That's a shame, because the car can reach that velocity with less than two miles of clear, straight road to work with. It's too bad that cars like this are throttled by their computers just when they're starting ti stretch to their legs -- although it's nice to know that my el-cheapo -- by comparison -- $8,500 sport bike has 20-something more MPH on the top end.)

Unlike my bike, though, the Jag has a luxurious ride, every amenity -- even an Active exhaust system that modulates the pitch and lets her rip when you're running hard, but quiets it down to a civil burble when you're not.

(My bike is always loud.)

Another thing about the XKR to cheer are its amazing Active headlights. They may be the best I have ever tested so far. The illumination they provide -- on regular beam -- has to be experienced to be appreciated. They turn night into day like a nuclear burst -- and not just in front of you but to the side and all around, projecting an expanding cone of comforting white light ahead of you for 50 yards at least. In rural deer country -- where Bambi jumping onto your hood is a common experience -- lights like these can save your life, in addition to a trip to the bodyshop. And then there's high beam -- which you may never even feel the need to use.

There are only two things I disliked about the new XKR after spending a week with one. First -- and like many vehicles at this price point -- the Jag has one of those over-designed, overly complicated "command interfaces" (in this case, a touch-screen multi-function display) for accessing the controls for things like the audio and GPS. Though the design eliminates a lot of clutter from the dash area, it can be aggravating and distracting to do basic things like change from FM to satellite or call up the map. The better systems out there have secondary manual-style knobs and buttons to allow the driver to bypass the computer "interface" -- but not the Jag. (There are, at least, manual knobs for some climate control functions -- but if you want to operate the heated seats or defroster, for instance, you still have to "scroll through the menu." )

The system is difficult to use under ideal conditions; but on days when the sun's glare hits the screen, you sometimes can't see a thing. There is, unfortunately, no tilt mechanism (or hood) to minimize glare. It's unfortunate that such an otherwise wonderful driver's car has an essential system that can make driving exasperating at times.

The other thing is the XK's Stalinist, over-intrusive traction/stability control system. There is an "off" button on the console -- but the system is still going to second-guess your driving no matter what. Forget about power-braking launches and the hooligan fun of laying a little rubber now and then. Big Momma says no. That may save some tread life, but it really takes away from the fun. I'm all for traction and stability control -- particularly when the car is very powerful -- and rear-wheel-drive. The system makes the car reasonably safe in poor weather (when all that power combined with a light rear end and high-performance "summer" tires can make such a car overly prone to fishtailing dramatically, unexpectedly -- and therefore, dangerously). But "off" should mean "off." If you want to lay some rubber, you ought to be able to do that.

Didn't you just pay six figures for the privilege?

Probably this last complaint can be hacked into submission. Pull a fuse, reprogram the computer -- smash something under the dashboard. Etc. But it should not be necessary. This is an enthusiast driver's high-performance GT -- right? Buyers should not be treated as though they're too idiotic or incompetent to be allowed free reign with all 420 horses whenever -- and however -- they wish.

As for the computer hassles -- that's a more subjective call. Apparently, this is what buyers in the XK's segment and price point want and even expect. I don't get it myself. But I am too poor to afford an XKR.

And that may be why I don't get it!

Still, it's an important thing to be aware of -- and to be certain you're comfortable dealing with on a day-to-day basis -- before you make your decision.