My brother the doctor drives a dull grey 1989 Nissan Sentra with 384,000 kilometres on the clock.

"It's a perfectly good car," he explains. "There's nothing wrong with it."

It does have the remains of a sporty stripe kit, I suppose, but for him it's simply a transportation appliance: a means to an end.

However, he did seem to like the red 2003 BMW Z4 in which I recently arrived for a visit. Maybe, with this $65,000 two-seat roadster, he caught a glimpse of a whole other world of automobile driving.

At one point I'm sure I saw him mentally chewing on this as he instinctively ran his hand along the fender. Maybe -- his mind was groping for this conclusion; I could see it in his furrowed brow -- maybe he was missing something.

That's what I've been telling him for years. While his Sentra is a sturdy pack mule, cars like the Z4 are thoroughbreds that will transport you to another automotive dimension. In fact, arriving at your destination is probably the most disappointing thing about driving them.

That's not to say the Z4 is beyond criticism. Several knowledgeable people report that this model, which replaces the Z3, is controversially styled and may face problems in the marketplace because of this.

But I received almost nothing but enthusiastic and positive comments about my Bright Red test car with black, Oregon Leather upholstery.

People actually yelled from their vehicles, gave me a thumb's up, waved or swooned jealously as I motored by.

Many times I asked strangers pointblank:

"Do you like the looks of this car?"

"It's fabulous," was the straightforward consensus from both men and women.

"What a sexy-looking car," was another common response, especially from women.

"So you don't think it looks kind of, you know, controversial?" I asked.

"No!" (Like, what are you, some kind of moron?)

When enough people tell you you look great, sooner or later you start to believe it. So it was that I began with an unclear opinion of the Z4 -- it is at the very least dramatically styled -- and ended up appreciating the fact that this car is different, flashy, exciting, clever and bold.

And I liked being seen in it.

Under the Z4's huge aluminum hood and between its deliciously long front fenders is a dual-overhead camshaft, 3.0-litre straight-six engine that makes 225 extremely smooth horsepower, enough to propel it from 0-100 km/h in 6.3 seconds (a 2.5-litre version making 184 h.p. is also available).

The signature sheet metal is truly distinctive. The panels are crafted with cheeky bulges, swooping planes, complex curves and contrary angles. It's a busy surface, for sure, and far more striking than the BMW Z3. The fender-mounted turn signals, capped with the large BMW roundel, are a superb finishing touch.

Aside from its sculpted surface, the most obvious visual feature is that this car is all hood. Two-thirds of the vehicle is in front of the driver, and in that sense it echoes sports cars of old, like the Triumph TR6, "E" Type Jaguar and, closer to the Z4's spiritual home, the BMW 507 (I say spiritual home because the Z4 is built at BMW's Spartanburg plant in South Carolina).

Indeed, the experience of driving the Z4 is reminiscent of all the good things about traditional roadsters, with all the bad things pretty much worked out. The cockpit, for example, is very simple. There's a speedometer, tachometer, fuel and temperature gauges, rotary light switch, gearshift and steering wheel. A single panel controls heating, air conditioning, the radio and an in-dash CD player. That's just about it for the controls.

The power convertible top is lined, and raises or lowers in 10 seconds. When raised, it's power-sealed by the side windows. (The 2.5 gets a manual top, with the power top available as an option.)

The seats provide ample lateral support and are firm but comfortable. They have plenty of travel and adjustability, and there's lots of room for your elbows and knees.

It took a while to appreciate the dashboard. It's very much BMW, and that, I think, is the key to "getting it." It's clearly not a Porsche, not a Jag, not a Mercedes. At first the instruments seem small, but then you rather fancy the chronograph-like precision of the dials and the stiletto sharpness of their pointers.

Similarly, the Bauhaus simplicity of the brushed aluminum facia and radio/heater/air conditioner module is distinctive, functional and understated.

On the road, the six-speed manual shifter is quick and accurate. It's easy to feel what gear you're in, and to find the next gear. You can heel-and-toe with abandon, and the engine accelerates with turbine-like smoothness and a sudden extra push at about 3500 r.p.m. Cornering is sharp and I never approached the car's limits, which are well beyond anything legal on public roads.

An array of electronic assists help to keep the car pointed in the right direction, and final drive is a lazy 3.07:1, giving you excellent mileage for long trips (although that advantage is lessened by the smallish 55-litre fuel tank).

The electromechanical steering is controlled by a servomotor, and firms up the faster you go. Cars with the optional Sport Package receive Dynamic Driving Control (sport mode) selected with a button on the centre console. This further tightens the steering and provides a quicker throttle response. Also included in the package are 18-inch ellipsoid wheels with 225/40R-18 front and 255/35R-18 rear W-rated tires. At $1,700, the Sport Package is a bargain, and the styling of these wheels, like many of BMW's wheel creations, is perfect for the car.

The chassis is rigid, with no cowl shake even on the bumpiest of surfaces. In most conditions the firm suspension is wonderful, negating body-roll in corners and providing a smooth ride on the highway. But when the pavement is uneven, the ride can be very choppy (it's hard to have it both ways in any car, however). By no means is this a bugs-in-the-teeth driving experience, but it's definitely at the minimal end of the roadster spectrum, and in my opinion, all the better for it.

Available space in the useful but diminutive trunk is maximized by the lack of a spare tire. Compensating for this are special "run-flat" Bridgestone Potenza tires.

My main criticism has to do with rearward visibility when the top is up. With no quarter-panels and a smallish rear window, you can forget shoulder-checks when you change lanes. Set your mirrors way out and you'll see what's coming from either side, but this requires an experienced driver behind the wheel. The top also creaks noticeably when it gets cooler outside.

For some reason, the speedometer is angled away from the driver, obscuring the numbers at the higher end of the gauge. It's not dangerous, it's just odd.

Under the hood, the engine could be dressed up more. The dark, ceramic intake manifold, plastic covers and black strut braces do little for an impressive engine bay. Finally, the doors don't shut with the vault-like sound I'd like.

But overall, the car is a feast for people who like fine details and functional simplicity, power and refinement, edgy design and traditional, sports car attributes.

It's a thrill to approach the Z4, drop into the seat, fire up the motor and hit the road. Every time.

2003 BMW Z4 3.0I

Type: Roadster, rear-wheel-drive

Seats: Two

Price as tested: $64,940 plus $1,145 freight and preparation (base: $59,500)

Engine: 3.0-litre straight six-cylinder, dual overhead camshafts; 225 h.p. at 5,900 r.p.m., 259 lb.-ft. of torque at 3,500 r.p.m.

Transmission: Six-speed ZF Type H manual

Wheelbase: 2,495 mm (98.2 in.)

Tires: Bridgestone Potenza RE050 RFT run-flat

Brakes: Disc/disc with antilock, Dynamic Stability Control (traction and stability system), dynamic brake control and dynamic brake force distribution

Curb weight: 1360 kg (2,992 lb.)

Coefficient of drag: 0.35

Standard features: Bi-xenon headlights, front, side and knee air bags for driver and passenger, heated seats, climate control, fog lights

Options: Premium package ($3,200, includes power-fold mirrors, auto-dimming mirrors, electric seats with driver memory, automatic climate control, HiFi audio); Sport Package ($1,700, includes Dynamic Driving Control, 18-inch ellipsoid alloy wheels); headlamp washers ($390), rain sensor with auto headlamps ($150)

Consumer Reports predicted reliability: NA (previous model: better than average)

Fuel consumption, L/100 km (m.p.g.): City 11.4 (25), Hwy 7.4 (38)

Fuel: Premium

Warranty, yrs./km: 4/80,000 with roadside assistance, 3/60,000 scheduled maintenance