The ideal touring car makes itself transparent to the driver. The driving experience is noticeable, not the vehicle providing that experience. Anyone test-driving such a car has to consciously force attention through to the vehicle instead of simply enjoying the ease of motion, the willingness of the engine, the responsiveness of the brakes. The testing driver has to notice what the designers have worked to make seamless. I made myself notice and allowed myself to enjoy.

To maintain peak performance athletes might clamp an oxygen mask to their face. That's what an engine is doing with a turbo- or supercharger: forcing more oxygen inside. While a turbo comes into play after the engine is spooled up a bit, the supercharger is there from the get-go.

The 3.8-liter V6 in the Grand Prix is normally aspirated in the GT model but supercharged in GTP versions. That lowers gas mileage slightly, but accounts for the addition of 60 horsepower (to 260) and the reduction by some two seconds in the time it takes to reach 60 mph from zero. We're talking just 6.5 seconds in the Comp G, a comforting figure when merging or passing in tight situations. At that the gas mileage is respectable: The GT gets 20 city and 30 highway with two mpg less for the supercharged versions.

Usually when power even approaching 200 hp is put through the same wheels that steer the car (i.e., the front wheels) a phenomenon known as torque steer ensues. This is that disconcerting tug at the steering wheel under rapid acceleration. It's like the front wheels are in a race with each other. Happily, there's little to no torque steer in the 2004 Grand Prix. Pull away smoothly with the right foot down hard and the Grand Prix is as stable as an Acura.

The four-speed automatic shifts in smooth increments. An electronic control system (ETC) has a speed-based response mechanism meaning that the car is tractable around town without goosey overreaction but answers the call for power instantly at highway speeds.

The Comp G has steering wheel mounted shifting paddles, more thumb-controlled buttons really, called TAPshift (Touch Activated Power). Unlike the road-car systems modeled more closely after Formula 1 (left paddle for downshifts, right for upshifts) the controls in the Grand Prix both do the same thing: press down on either to select a lower gear, up on either for a higher gear. (All is controlled so you can't over-rev.) Quick to respond, TAPshift is a way to experience the control of a manual in hard pushing while retaining the leave-it-be ease of an automatic for stop-and-go crowds.

The ride quality of a car is perhaps on a par with styling when it comes to subjectivity. The traditional American ride is far softer than the traditional European ride. But disappearing is that extra-soft billowiness that separates a car from the surface it's riding over and is thus dangerously misleading in turns. Why that American ride is going away could be because those who've preferred it are spending more time in rockers and less on the road. And, too, because suspension engineers are finding ways to allow for some softness on the straights and yet snug down to business when it comes to serious cornering. (Improved chassis rigidity is one example.)

The ultimate feel of the road, and thus a car that loves quick kinks and endless esses, requires a tight suspension. The knit-back gloves driver is grinning, but others may be groaning at a ride too rough for them.

I separate suspension systems into three levels. One: you can't tell what your tires are running over on the road except that it's pavement. Two: if you run over a dime you'll know it. Three: you not only know it's a dime you know what year it was coined.

These levels are descriptions, albeit extreme, of what the engineers have brought about in the three Grand Prix models. The GT offers the most traditional ride; the GTP is tighter for secure cornering yet retains enough ease to satisfy the soft-ride devotee.

The Comp G itself is grinning through the corners. And why not? Its suspension system renders it capable of 0.83G lateral acceleration force. Included in the Comp G package is StabiliTrak Sport, a four-wheel stability system that is unlike anything in the market segment. You'd grin too. And it does it without jarring a tooth on the straights. Nicely done, suspension guys. As for stopping, the brakes in the 17-inch wheels of the Comp G pull it to a stop from 60 mph in 139 feet. Commendable and satisfying.