HENDERSON, NEV. -- Celine Dion is building a huge house here on man-made Lake Las Vegas and I am wondering if she needs a $81,350 convertible for the 40-minute commute to Caesars Palace.

If so, there is this spanking new Audi S4 Cabriolet to consider. That's what I'm thinking as Axel Mees, the new head honcho at Audi North American, waxes on and on about how Audi is just now rediscovering America, 500-plus years after Christopher Columbus. Frankly, he seems a bit defensive.

He has reason to be. Audi is outsold 3-1 in North America by its main German rivals, Mercedes-Benz and BMW. The numbers are even worse against the Lexus.

"Yet Audi outsells BMW in all European markets except the [United Kingdom] and Greece," said Mees.

Audi has loads of work to do in North America if it's going to catch BMW and Mercedes. Mees concedes that Audi in Germany has long ignored the advice of its North American distributor, so Canadian and U.S. buyers have often found Audi showrooms filled with cars they didn't want to buy.

The S4 Cabriolet I'm here to drive clearly exists not to make a lot of money -- Audi plans to sell just 80 in Canada and another 400 or so in the U.S. -- but rather to give the brand a boost. Mees isn't so crass as to say so, but it is why Audi is launching a 340-horsepower convertible that will go from 0-100 km/h in about six seconds and corner like the Roadrunner being chased through the desert by Wile E. Coyote.

But Norbert Seitner, Audi's head product planner on this continent, comes close to admitting as much. "If you want to be a premium manufacturer you have to prove it -- you have to raise aspirations and have a halo car," he said.

By offering a ragtop halo to compete with the Mercedes-Benz CLK55 AMG Cabriolet ($110,590), BMW's M3 convertible ($83,950) and even Jaguar's luscious XKR convertible ($117,000), Audi is making a statement about its engineering capabilities -- which are considerable, even if generally underappreciated in Canada and the United States.

This is proven in a test drive that takes us all over Nevada's deserts. I don't spot a single road runner or coyote, but I am amazed at the sights in the famed Valley of Fire with its jagged, fiery red sandstone formations reaching into the clear blue sky.

Seitner says the S4 cab is essentially an Audi S4 (new last year) with chassis reinforcements to compensate for the lack of a permanent roof, as well as its own badging, different bumpers and a modified engine intake. Also, there is no rear spoiler because wind tunnel testing found one would offer no aerodynamic benefit in an open air car. That and the composite trunk lid hiding the antenna wouldn't take a spoiler.

With the talking done, we are off for the Valley of Fire. Our route takes us northeast of Las Vegas on a circuitous run leading to Interstate 15, then a hard right and into the Valley of Fire just west of Lake Mead. All around is a dry desert with flowers in spring bloom. I notice but don't pay much attention. This S4 is too entertaining for that.

There's no shortage of power from the 40-valve V-8, which growls gently when you goose the throttle. With Quattro all-wheel drive and a standard stability control system, the S4 is balanced and sure-footed in all driving and weather conditions, but compared to the M3 droptop, this car is pretty mellow.

Slithering down Route 168 towards Glendale, the S4 with its aluminum suspension resists roll. The sharp driving responses are courtesy of slightly aggressive spring rates and revised shock-absorber damping (courtesy of 31- and 20-mm hollow anti-roll bars, front and rear). Yet on rougher pavement, the ride feels nicely firm, but not rough.

I do find the over-boosted power steering is too light, though quick and precise. The six-speed manual shifter is as satisfying as the M3's, which is saying quite a lot. A six-speed automatic with Tiptronic mode is available for an extra $1,340 (bringing the sticker to $82,690).

Audi programmed a relatively high threshold for intervention of the S4's traction-control and stability-enhancement programs, so the driver feels in charge. At each corner the S4 is shod with chunky 235/40R18 tires on the signature Avus six-spoke wheels. Powerful brake discs all around are there to keep you under control.

Under the hood, Audi has stuffed in a 4.2-litre, 40-valve, four-cam V-8. This was no easy job. In fact, Audi was only able to wedge the V-8 under the hood after moving the cam drive to the rear of the engine and substituting a chain for the standard toothed belt.

The result is one of the most compact V-8s anywhere, one that spins up beautifully to 340 hp at 7,000 rpm, and 302 lb-ft of torque at 3,500.

Powerful and sure-footed as it is, there are few visual clues in the styling. The S4 does not ride particularly low, normally a sign of a high-performance car. You will find fairly large front air intakes and titanium-hue headlight surrounds, though. But as a whole the package is understated.

Inside, the dash sports carbon-fibre trim and grey-faced S gauges. Again, this is not a showy look. Pop-out cup holders are so shallow they'd be dangerous if you loaded them up with steaming hot coffee. And storage space is extremely limited.

Lastly, the top. It is power-operated, fully insulated, goes up and down in 24 seconds with the push of a button and has a glass rear window. When down it sits under a trunk-lid-like panel, tucked away so as not to interrupt the car's styling lines. Very nice.

So would Celine like it? I think it's probably not flashy enough for a Vegas showgirl like her, and besides, she works for Chrysler. I like it, though it does have a fat sticker price and, given we're talking about a prestige car, this S4 looks a little tame, even bland.

Specifications

2004 Audi S4 Cabriolet

Price: $81,350

Engine: 4.2-litre V-8 DOHC

Horsepower/Torque: 340 hp/302 lb-ft

Transmission: Six-speed manual or six-speed Tiptronic automatic

Fuel economy: City 15.8 L/100 km; Highway, 10.2 L/100 km (manual transmission)

Alternatives: Mercedes-Benz CLK55 AMG Cabriolet, BMW M3 convertible, Jaguar XKR convertible

Like: All-wheel-drive grip, silky engine power, balanced driving responses, year-round driving in a convertible

Don't like: Feather-light steering, overly understated looks, shallow cupholders, limited storage space