Kohler, Wisconsin - The conventional way to build a roadster is to take a coupe, cut off the roof, add strength to the chassis (and weight) and hope that the result looks half decent and drives not much worse than the car on which it is based.

BMW, in the last few years, has defied convention. Its current designs for the 7-series, 5-series and even the three have been unconventional and controversial. Although I count myself among those who like the current design approach, the conventional wisdom has it that BMW messed up a good thing.

When the Z4 roadster was introduced in 2003, it too received mixed reaction from auto writers who felt the pugnacious appearance of the previous generation Z3 had somehow been compromised. Critics focussed on one design element, the opposing diagonal slash on the fender, as evidence of design gone wrong. Diverted by BMW's unconventional approach to design, it was easy to ignore the car, which is a vast improvement in every respect over the Z3.

With the newly arrived M Coupé, BMW has again tossed convention out the window. Instead of cutting the roof off a coupe to create a roadster, BMW has added a roof to a roadster to create a coupe.

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The result is stunning. And anyone looking at both coupe and convertible would never imagine that it was the roadster that came first and not the hard top. The overall appearance is so classically perfect that one cannot obsess on an unusual design element and ignore the overall package.

Viewed from the rear quarter, the M Coupé is breathtaking in its beauty, a look that blends modern elements with classic sports car design. The long hood and short sloping back brings to mind fastbacks of the past, cars that would top any enthusiast's list of gorgeous automobiles, cars like the E-Type Jaguar, '63 Corvette Stingray, '66 Mustang Fastback and Ferrari GTO.

With the exception of its roof, the M Coupé has much in common with the M Roadster. The engine and transmission are the same of course, and both have the same interior appointments:

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heated Nappa leather sport seats, and leather trimmed door panels, console armpad, kneepads, handbrake grip, shift knob and fat leather-wrapped steering wheel. Aluminum trim with a hexagonal pattern adorns the dash and centre console. Standard equipment includes automatic climate control, Xenon headlights, speed-sensitive rain-sensing windshield wipers, heated windshield washer jets and tire pressure warning system.

The engine is the super smooth 3.2-litre inline 6-cylinder also found in the M3 Coupé and Cabriolet. With 330 horsepower, 60 mph (96 km/h) comes in just 4.9 seconds compared to 5.6 seconds for the 255 hp 3.0-litre inline six found in the Z4 3.0 si. A free-flowing exhaust rewards your right foot with the sweet sound of a high-revving inline six, but the noise is less intrusive than in the M3.

With 262 ft-lb of torque at 4,900 rpm, the 3.2-litre has plenty of power across the mid-range, but if you forget to downshift, it will pull from 1,500 rpm in fifth, albeit gently at first. But with its horsepower topping out at 7,900 rpm, you will rarely use fifth gear. And sixth is strictly for freeway cruising.

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Throttle response is adjustable via a console switch that alters the ratio of throttle opening to pedal movement enabling quicker engine response to driver input when desired.

Numerous performance upgrades differentiate the M Coupé and Roadster from run-of-the-mill Z4s. The M versions have a wider track front and rear, beefed up suspension components and tires (225/45ZR-18 front and 255/40ZR-18 rear) borrowed from the M3. The wheels are the same 18 x 8.0 front and 18 x 9.0 rear size found on the M3 but have a unique design with an open configuration to get cooling to the brakes. The four-wheel disc brakes are taken from the M3 Competition Package and feature elaborate cross-drilled rotors that eliminate deformation under hard braking. Also borrowed from the M3 is hydraulic power steering which provides more precise steering and better feedback at the expense of increased effort in parking and low speed driving. Dynamic stability control (DSC) is standard equipment.

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After half a day behind the wheel of the 2006 M Coupé, travelling around country roads near Elkhart Lake, Wisconsin, and several laps around nearby Road America, I can say that the coupe's steering is as advertised and the brakes are as breathtaking as the car's attractive skin. However, a day that waffled between drizzle and downpour prevented us from exploring the outer limits of the M Coupé's handling and traction.

On the track, the M Coupé did display nice balance, thanks to a nearly perfect 50.2% front/49.8% rear weight distribution. The six-speed manual transmission moves quickly and precisely from gear to gear, while the clutch is firm but light. Unlike other M models, the 7-speed sequential manual transmission is not available. People who like traditional shifting won't miss it.

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The ride quality is surprisingly comfortable considering the firmer suspension given the M. This is a car you will enjoy all day, without discomfort, and when the desire to get going overcomes, there is that sport-mode button on the console to quicken the pace.

Will the M Coupé provide the three-season driving enjoyment most enthusiasts desire? Absolutely. Is it the car that will give you the Solo 1 championship? I really can't say.

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The M Coupé is priced in Canada at $68,900, just $8,000 more than the Z4 3.0 si. Considering that a fully automatic soft top, heated seats, DSC and 18-inch wheels would add more than $3,500 to the cost of a Z4 3.0 si, the M Coupé's price premium seems like a good deal. And compared to competitors such as the Porsche Cayman S ($83,900) and Mercedes-Benz SLK55 AMG ($84,050), the M Coupé looks like a price leader.

Optional equipment is limited to a navigation package ($2,900) and a premium package ($2,700) that adds power folding and auto dimming mirrors, power memory seats and upgraded stereo. A six-disc CD changer is also a $795 option.

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