Here's a car that lets you enjoy that wind-in-your-hair fun not with just one passenger, but with as many as three. With two-plus-two seating and a punchy turbo engine under the hood, the BMW M240i Convertible boasts a promising spec sheet from the outset. Moreover, the remains, in my view, the most enthusiast-friendly model range that BMW currently offers, with great dynamics in all its three (230i, M240i, M2) variants. Surely that makes this topless, fun-in-the-sun version a home run?

The 2018 BMW M240i Convertible is a thrilling top-down sports car

+42 More

See all photos

Let the sunshine in

When it comes to the primary duties of being a convertible, the BMW 2 Series handles them with aplomb. Lowering the powered soft top at the push of a button takes just 22 seconds and, better still, you can perform the convertible ballet while moving at up to 30 miles per hour. If, say, it were to start pouring down while you were driving home from the airport, that might come in handy… not that I'd know anything about that. When the top is up, it's remarkably well insulated against wind and road noise. This is not a convertible in which you have to crank the radio to hear your podcast on the highway.

It is, however, a convertible in which you can bring more than one friend -- something we can't say of Roadshow favorites such as the or pricier options like the or . Like many two-plus-two  convertibles , the rear seats are best used with the top down (so there's unlimited headroom) and either for children or for short journeys. Legroom is tight at all times, and headroom is on the short side when the roof is raised.

With the top raised, the modest trunk opening admits access to 11.8 cubic feet of storage space. But because the roof lowers into the trunk, that figure falls to a less-than-impressive 9.9 cubic feet during topless driving. It's a lot less roomy than the 2 Series coupe, in which you can even fold down the back seats for more storage. Still, those figures aren't too bad when you look at the space offered in the trunks of rival convertibles: 9.9 cubic feet top-up and 7.1 top-down in an , 11.4 cubic feet in a Ford Mustang droptop and just 7.3 cubic feet in an open-air Chevy . For reference, I fit a carry-on suitcase and a backpack in the trunk without much fuss.

It's a sharp-looking car, too, with its lower half carrying over the sharp creases of the BMW 2 Series coupe. Rear-wheel-drive proportions give the car a sporty stance, with its wheels pushed out to either end of the bodywork. And being the M240i version, my tester wears striking 18-inch wheels, darkened trim and a more aggressive front fascia.

Top-up, the fabric roof fits snugly down against the decklid, still providing plenty of visibility thanks to a large rear window and generously sized quarter windows. With the roof lowered, plastic panels cover up any untoward openings in the bodywork, making for a tidy look. There's even a fold-out plastic windblocker that can be installed over the rear seats to keep your hair unmussed, but it's so fiddly I left it in the trunk during my test.

If only the interior was so Instagrammable. While there's no faulting the straightforward layout of the BMW's secondary controls, there's also no real design flair in the cabin. Aside from a shiny metal dead pedal, some aluminum-look trim pieces and the Oyster-colored faux-leather upholstery, the inside of the M240i sports a whole lot of black plastic. That's a letdown considering this car's price (more on that later). Worse yet, this is basically the same dashboard design from every BMW I've been in for the past decade -- isn't it time for a refresh?

Performance to spare

Not that I'm too focused on the interior plastics once I get the BMW M240i out of the city. Its turbocharged 3.0-liter inline-six is a punchy thing, dishing up 335 horsepower and 369 pound-feet of torque. The 4.5-second sprint to 60 miles per hour is an impressive stat, but more telling is the amount of instant shove the engine can deliver at all speeds. The eight-speed automatic transmission readily downshifts to unlock more power, yet is supple and inconspicuous most of the time. There's a noticeable change in the powertrain's responsiveness between Eco Pro, Comfort, Sport and Sport+ modes, but even in the default Comfort it's eager to dish out more turbo boost and acceleration.

Fuel economy is rated at 21 miles per gallon city, 30 mpg highway and 24 mpg combined, all on premium fuel; I easily matched the combined figure in my week behind the wheel. That's a decent, if not outstanding, figure for a convertible with this much performance.

The M240i steers sweetly, too, thanks in no small part to the grippy Michelin Pilot Super Sport tires, which even have a staggered sizing (225/40-series in the front, 245/35 in the back). Being a BMW M-tuned model, this car also has enlarged M Sport-branded brakes as well as an adaptive suspension that varies between compliant and poised ride-and-handling balances at the touch of a button. Where some of BMW's newer models can feel detached and aloof on the road, the M240i still teases me into playing and driving harder all the time.

In terms of in-car tech, the iDrive infotainment system is excellent. With both a touchscreen and the familiar center-console jog dial, navigating the system's menus is a cinch. My test car has a Wi-Fi hotspot, wireless phone charging and navigation, too. Things are less than stellar for smartphone users, though, as Apple CarPlay remains a paid option and takes several menu steps to configure, while Android Auto isn't offered at all.

Active-safety technologies are part of a $500 option package (not fitted to my test car) called Active Driving Assistant. That package includes lane-departure warning, precollision warning and precollision braking. My test car also featured automatic high beams and parking sensors, the latter of which includes a self-park feature and costs $800. Adaptive cruise control is an option on the 230i but unavailable on the M240i. BMW says that the radar unit would take too much space away from the engine's cooling ducting for the M240i to cope with track driving.

What competition?

The four-seat convertible is a shrinking market segment and finding a rival to this M240i Convertible is tough. The Audi A3 Cabriolet is a close match, but it's offered only with a 220-horsepower engine that more closely matches the BMW 230i; no S3 Cabriolet is offered. Perhaps instead the 2 Series competes with the convertible versions of the Ford Mustang and Chevrolet Camaro. After all, those similarly offer rear-wheel drive, two-plus-two seating and healthy helpings of power.

The 2018 BMW 2 Series convertible starts at $41,595 for the rear-wheel-drive, 248-horsepower 230i, with its all-wheel-drive xDrive version listing for $43,595. Then the M240i is $50,895 or $52,895 with xDrive. This tester has a handful of options -- CarPlay parking sensors, navigation, heated seats and steering wheel, LED headlights and so on -- which boosts the as-tested figure to $56,345. Good as this car is, that starts to feel like a lot of money. The larger convertible, after all, can be had from $53,945.

Ultimately, the BMW M240i Convertible is a special car because there are so few things that match up to it. It feels more premium than the aforementioned pony cars (even if they offer way more features) and more exciting to drive than the A3. It's a just-right mix of sportiness, fun and everyday practicality. In 2018, it's a little hard to swallow the short equipment list and plain cabin, especially given this car's as-tested price, but there's still a lot of appeal to this sporty soft top.