Anyone who claims to know anything about BMWs will tell you that if you’re looking for an M3, a proper golden-era driver’s car, this 2003 BMW M3 Convertible is the wrong one. They’re soft-edged, overweight cars for posers.

I adore the open-top driving experience, but I’ve always struggled with cars that weren’t meant to be convertibles. For example, the Porsche Boxster, was designed from the ground up to not have a fixed roof, is a car that I love. A 911 Cabriolet, which is a convertible version of a fixed-roof car, rubs me the wrong way on principle, because it wasn’t supposed to be this way. It’s a compromised product. If you want a roadster, get a roadster.

For the uninitiated: a roof adds a huge amount of structural rigidity to a car. Imagine twisting a ladder, versus twisting a cage. A stiff structure is crucial in so many ways, it’s one of the rare cases where more is always better. If the car isn’t flexing through a corner, the suspension geometry can function more consistently, and handle and feel better. This also has the side effect of greatly improving ride quality and overall refinement. More stiff equals more good. Every time.

Back to this Bimmer: if it’s a platform that has shared duty, especially with a car like 3 Series, where it has to be a sedan, a wagon, a coupe, and a convertible, things get messy. It’s designed around having a fixed roof to add structure, then when the convertible loses that roof, BMW has to rebuild that structure, often through extensive chassis bracing. Along with suspension tower braces on top and X-braces underneath to help tie it all together, the rockers and door sills have a ton of extra material added to keep that ladder stiff. All this makes convertibles considerably heavier than their coupe counterparts. Weight is the enemy of performance, handling, acceleration, efficiency, and ride quality. Less weight equals more good. Every time.

So, I had low hopes for this M3 convertible. I never liked these specifically because I always heard they were the wrong one. I figured since I’ve never driven a BMW with the last-of-its-kind S54 inline-six engine, I’d focus on that. The thing is, approximately 35 per cent of all E46-generation M3s were convertibles; they did exceptionally well. And now, having spent some quality time with this one, I see it. You could buy an M Roadster—Z3 or Z4—and have a far better sports car, but the M3 ‘vert is a far more accomplished vehicle, with back seats and a real trunk, that still hits all the right notes.

Most of those notes are being hit by the aforementioned S54 engine. It’s less a derivative of the M54, more an evolution of the race-bred S50 that debuted in the 1990s. It went on to make up the foundation of the V12 powerhouse in the earth-shattering McLaren F1 supercar—which was still the fastest car in the world when this M3 was built. This 3.2-litre normally aspirated inline-six makes 332 horsepower, 278 pound-feet of torque, and unlike literally every other gas engine BMW was building at the time, still had an iron block. For strength.

Part of the necessity for iron was the very tight four-millimetre spacing between cylinders to keep the engine light and compact. Another part of it was the fact that it could rev out to eight thousand—unheard of in a street-bound straight-six before or since. Even purpose-built tuner engines don’t typically go that far. Those pistons are already screaming up and down in their bores incredibly fast, among the fastest ever seen in a stock motor even to this day. It’s still a monument of engineering.

And it’s still delicious to drive. Breathing through individual throttle bodies, this engine has all the character and presence of an engine twice its size. It’s glass-smooth no matter what, and without tricks like active engine mounts, it’s just your right foot and the raw, harmonic merit of a good engine. Despite it being so high-revving, it never feels peaky or high strung. Instead, using BMW’s trick VANOS variable valve timing system on both cams, it delivers a healthy amount of seamless torque off idle. It keeps building in a dead-linear fashion all the way up to its power peak of 7,900 rpm—right before its 8,000-rpm redline.

It’s weird to drive a straight-six that revs that high. When I first jumped in, I was aware but not really thinking about it. It’s a 3 Series—albeit a now-classic E46—possibly one of the easiest cars in the world to just jump into and go. The cabin space is lovely, ergonomically sound, and driver-centric. The seating position is perfect, the clutch is easy to read, and the shifter is typical BMW—long-ish but satisfying. Throttle response is crisp and organic; there’s a very immediate sense of rightness to it. There’s a reason why these cars cleaned up almost every comparison they were a part of in their day.

Once I get onto the open road, I’m suddenly having a much better morning than I expected. Sure, an E46 M3 coupe is lighter and tighter, but you can’t really feel that on the hilly, usually straight-as-an-arrow roads in rural Ontario. But you can feel the sun and the wind, and you can hear the engine so much better. It almost shrieks through its individual throttle bodies. Every little blip of the throttle sounds properly exotic, backed by a familiar Bavarian baritone harmony that builds in volume and pitch until about 6500 rpm, where you’d usually be shifting into the next gear.

Beyond that, it turns into a different animal. The song turns into a scream, a manic mechanical wail. It would almost sound wrong; a cry against the laws of physics if it didn’t feel so right otherwise. It’s so smooth and wind turbulence is so well controlled that speed sneaks up on you. It isn’t alarmingly quick like BMW’s modern turbo engines, but it’ll comfortably put your licence in jeopardy without you realizing it. And you’ll want to let it keep going after you do realize it.

This car isn’t all about its engine. The E46 M3 is heralded as one of the best-handling cars ever built. Despite lacking a fixed roof to hold it all together, it still feels fantastic to hustle through corners. The steering and chassis feel still remains a high watermark today, turn-in is sharp, mid-corner balance is terrific, and you can dial in as much oversteer as you want via the skinny pedal. Pedal placement is terrific for fancy footwork, and brake pedal feel is firm and linear. The E46 M3 is such a joy to drive and inspires so much confidence.

With the exception of the engine, there’s nothing really extraordinary about this generation M3. Even in the case of the engine, its real crowning achievement is how it’s able to behave in such an exotic fashion in one breath and be totally civilized in the next, without having to change drive modes or any of that modern malarkey. The rest is just absolutely nailing the execution of the fundamentals, the things that really matter in a car. Sound ergonomics, excellent controls, fine balance of athleticism and comfort. No gimmicks, no tricks, just excellent engineering and masterful execution in a cohesive experience. It’s remarkable.

This car, despite being lambasted as the wrong one, certainly doesn’t feel wrong. Packing one of the sweetest engines ever built, a playful chassis, a comfy cabin, and a driving experience like few cars before or since, this 2003 BMW M3 Convertible is made all the sweeter by being able to open up and let the world in as you let your let your worries fly away. This is no poser’s car. This car is still the benchmark.