Ah, but beware the infamous Mexican speed bumps. Hit one of these “sleeping policemen” at speed and you’ll end up sailing into the nearest cantina sans undercarriage.

Despite this 650i’s larger footprint, back seat accommodation falls into the “occasional” category. With two six-footers sitting comfortably in front, the rear perches are reduced to nicely upholstered parcel shelves.

2012 BMW 650i Cabriolet
2012 BMW 650i Cabriolet
2012 BMW 650i Cabriolet
2012 BMW 650i Cabriolet
2012 BMW 650i Cabriolet. Click image to enlarge

So it’s a 2+2 grand tourer, pure and simple. If you’re serious about carrying four adults in drop-top comfort, best look to the $77,500 Mercedes-Benz E550 Cab, the Maserati GranTurismo Cabriolet at $169,900, or the (ahem) Chrysler 200 Convertible, at $29,995.

I’d say the 650i Cabriolet’s nearest competitor is the $114,000 Jaguar XKR Convertible.

Built on the BMW 5/7 Series platform, the 2012 650i wafts its privileged passengers down the road courtesy of a twin-turbocharged 4.4-litre V8 that makes 400 horsepower at 5,500 rpm and 450 lb.-ft. of torque from 1,750 to 4,500 rpm. Power gets to the rear wheels via an eight-speed automatic supplied by German specialists ZF. (A no-cost six-speed manual transmission is available only in North America.)

This is an exceptionally smooth drivetrain, and there is always a great wallop of turbo torque only an ankle-flex away. The tranny shifts imperceptibly and responds to flicks of the paddle shifters as quickly as most twin-clutch boxes.

The blown bent-eight makes a suitably muted howl when caned, and on upshifts, you hear delicious “woofs” coming from the tailpipes. This engine isn’t as visceral as the previous naturally-aspirated V8, nor is it much of a revver, running out of poof around 6,000 rpm, but it surely does push this portly GT down the road with little effort.

With all the windows up, wind management in the cabin is quite good. With the multi-layer canvas lid in place, I doubt few buyers will wish for more isolation. This convertible’s structure is very solid, showing nary a hint of cowl shake.

Marking a first for the 6 Series, xDrive all-wheel-drive will be available in the Fall.

As with other BMWs, the available Dynamic Handling Package ($3,900) brings adaptive dampers, four-wheel steering and Dynamic Drive. A rocker switch on the console calls up four dynamic presets (Comfort, Normal, Sport and Sport+). These tailor the functioning of the adaptive dampers, throttle and transmission mapping, steering effort and stability control. As would be expected, the 650i is sharpest in Sport+, and over the sinuous mountain roads of our test route, our big red GT was swift and sure-footed.

If you fool yourself into thinking the 650i is a sports car, however, you’ll find yourself up against lazy turn-in, less than tactile steering and 2,056 kg (about 4,500 pounds) working against you.

So don’t drive it like that; you’re not supposed to. This car likes open roads and grand sweepers – and passing the proletariat in great gushes of turbo thrust.

The new 2012 BMW 650i Cabriolet is a supremely capable grand tourer in the purest sense, and will surely appeal to a wider (read: more conservative) audience than the outgoing model.

Of course, if it’s just a little too ‘Palm Springs’ and not enough ‘Nurburgring’ for you, there will be an M version of both coupe and cabriolet, packing a rumoured 570-hp/530 lb.-ft. version of this engine.

You’ll be wanting to tie those golf clubs down, then.

Pricing: 2012 BMW 650i Cabriolet
  • Base price:$106,800
  • Options:$24,000 (20-inch wheels, $2,000; Dynamic Handling Package, $3900; adaptive cruise control, $1,500; Executive Package (soft close doors, rear view camera, contrast stitching, leather instrument panel, surround view, head-up display, Sirius, upgraded audio), $6,900; Technology Package (high beam assist, lane departure warning, active blind spot detection, park assist, night vision) $4,900; Premium Seat Package (ventilated seats, Nappa leather, comfort front seats, active front seats), $4,500; Smartphone integration, $300).
  • A/C tax:$100
  • Freight:$1,995
  • Price as tested:$132,895

  • TBD

  • Jaguar XKR Convertible
  • Maserati GranTurismo Cabriolet
  • Mercedes-Benz E550 Cabriolet
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