Model changeover time always is challenging for companies that make popular cars.

One such company is Audi, which is enjoying ever- increasing sales in North America, thanks to an extensive, well-planned lineup that has something for just about everybody.

But somehow, Audi found a way to improve its lineup with an all-new Audi A4 for 2009.

The new model is somewhat larger than the current one, with a much stronger emphasis on performance driving and a heavy dose of technology. The A4 competes with the BMW 3 Series, Infiniti G35 sedan, Cadillac CTS and similar cars

The overall performance, handling and enjoyment of the car are greatly enhanced by the all-new Drive Select system that is optional on the A4. The system uses adjustable engine/throttle mapping, suspension damping and dynamic steering to alter the car's characteristics to suit the driver's preferences. You dial in what you want, and away you go.

So often, when automakers offer systems that allow for adjustments of these kinds, there usually aren't dramatic changes in how the car behaves. Not this time. Audi's Drive Select is a gem, and the changes you feel are quite dramatic. It's like being able to design and drive several totally different cars in one, depending on the settings. I highly recommend it.

Audi always has been known for terrific interiors, and this new A4 is no exception. The interior is contemporary and sophisticated, as Audi always has been, with supportive, supple leather seats that hold you gently in place, along with an adjustable center armrest.

As far as exterior styling is concerned, Audi has developed a new trademark for the styling of its models that now is being carried on to the new A4: the use of daytime halogen running lights that underline each headlight for a dramatic look.

There's a lot of looks that are similar to the A5 in the new A4, and that's a good thing. The Audi A5 is one of the most beautiful cars in the world, hands down. The A4 inherits a profile that is strikingly similar to the A5: smooth, flowing flanks with some well-placed character lines and a general look of relaxed elegance.

Problems?

I would have liked less softness and play in the Audi's steering system. The other concern with the new A4 is the sheer complexity of all the new technology. While the controls are easy to operate, they aren't intuitive. This is one car where the owner who skips reading the owner's manual will not be able to get the most out of what is a pretty terrific sedan.

Power comes from an all-new 2.0-liter, turbo, four-cylinder engine producing 211 horsepower that is expected to offer up to 15 percent better fuel economy, or a 265-horsepower, 3.2-liter V-6.

Fuel economy figures are not yet available. Prices range from $28,000 to $38,000.