According to most purists, a BMW sports coupe or convertible are supposed to have a smooth gasoline engine –preferably an inline-six- mounted up front and sending power to the wheels at the back.

The new 640d xDrive Coupe and Convertible that will debut at the Geneva Motor Show next month ticks only one of those boxes: the straight-six found under the hood. However, it's not fed by gasoline but by diesel fuel and it channels power to all four wheels.

It's not the first diesel-powered 6-Series as that taboo was broken by the previous generation model, but it's the first to combine an oil-burner with BMW's electronically controlled all-wheel drive system.

For owners of the new generation of the BMW 6-Series Convertible codenamed F12 looking to improve the looks and the performance of their drop-top model, Lumma Design has released the first details on its CLR 600 GT package that will debut in a couple of weeks' time at the Geneva Auto Salon.

The German tuning firm's offerings include a rather discreet exterior styling kit comprising a front apron with additional LED daytime running lights (wonder how long these will last…), rocker panels, blacked out kidney grilles, and a rear apron with a diffuser.

Have US$76,895 to spare? For that coin, you can get in the brand new 2013 BMW 640i Gran Coupe, which is the initial model of the Bavarian firm's sports saloon that arrives in the U.S. showrooms early this summer.

The 640i Gran Coupe is powered by a 3.0-liter turbocharged straight-six gasoline engine delivering 315hp at 5,800 to 6,000 rpm and 330 lb-ft of peak torque on stream between 1,300 and 4,500 rpm. Power channeled to the rear wheels through an 8-speed automatic transmission.

Despite the fact that the 6-Series Grand Coupe’s world premiere will take place in March at the Geneva Motor Show and the first cars won't be arriving in showrooms until next summer, BMW has already readied a media campaign for its spanking new sports saloon.

The global campaign, which will launch in print and TV media in the second quarter of 2012, features a total eclipse of the sun as the central theme and the motto “Beauty. Revealed”.

After the first pictures and details on BMW's new 6-Series Gran Coupe followed by our supplementary report on the M Sport Package and the live configurator, we're wrapping up our coverage on the Bavarian firm's answer to the Mercedes-Benz CLS with the official videos that include static and driving footage.

The most important things you should know about the Gran Coupe is that it rides on a 113mm (4.4-in.) longer wheelbase than the 6-Series Coupe to help make more legroom for the rear passengers, while the engine lineup remains the same and currently includes two turbocharged petrols, a straight-six and a V8, plus a six-cylinder diesel unit.

It didn't take long for BMW to launch an online configurator for its brand-new 6-Series Gran Coupe, which was unveiled this past weekend ahead of its first public appearance that is scheduled to take place at the 2012 Geneva Motor Show next March, for those fans who just have to build their own.

For now, the configurator offers users some basic options to pick and choose from such as the exterior and interior colors, the decorative trims and alloy wheel designs

We also get our first look at the M Sport Package that will be available from the launch of the four-door version of the 6-Series next summer.

It took BMW 20 months from the presentation of the Concept Gran Coupe at the 2010 Beijing Auto Show in April of 2010 to present the production version of its foray into the premium four-door coupe segment, the all-new 6-Series Gran Coupe.

The new model is essentially a four-door version of the latest 6-Series Coupe and will allow the Bavarian automaker to compete head on with the likes of the Mercedes-Benz CLS, Audi A7 Sportback and Porsche Panamera sports saloons.

Given that the original concept was production ready, it doesn't come to much of a surprise that the only styling changes made concern the lower part of the front bumper, the re-positioned reflectors on the rear bumper and the different tail pipes.

The Gran Coupe's exterior styling builds on 6 Series Coupe adding an extra pair of doors while keeping the low-slung appearance.

Measuring 197 inches (5,007mm) long with a wheelbase of 116.8 inches (2,968 mm), the Gran Coupe is 4.4 inches (111mm) longer than its 2-door coupe sibling, with most of the extra length going towards the rear passengers.

The B3 GT3 limited edition isn't the only Alpina making its debut at this week's 2011 Tokyo Motor Show as the boutique automaker also brought along the coupe version of its B6 BiTurbo based on the latest BMW 650i.

Alpina has taken BMW's 4.4-liter V8 turbo engine to the next level with a series of upgrades including an intercooled dual turbo system and the addition a new titanium exhaust system developed in conjunction with exhaust specialists Akrapovic, that all help to lift output to 540-horsepower at 5,500 rpm and peak torque to 700Nm (516 lb-ft).

Looking to offer enthusiasts more options for customizing the new 2012 BMW 6-Series Coupe, AC Schnitzer will unveil its new tuning program for the 650i at this week's 2011 Essen Motor Show in Germany.

Dubbed the ACS6 5.0i, the package includes a performance upgrade with unspecified modifications for the 4.4-liter turbocharged V8 engine that help lift output from 407HP to 540-horses.

One of the star attractions for automotive enthusiasts visiting the German city of Munich is BMW's recently redone 53,000 square foot museum. Along with the permanent exhibitions, the Bavarian brand's museum also hosts special events dedicated to a certain period or line of vehicles.

Starting from October 28, 2011 and until the end of September 2012, the BMW Museum will present a special exhibition devoted to the development of the firm's large coupe and convertible models throughout the years.

BMW announced that the third generation of its GT model, the 6-Series Coupe that was launched last April at the Shanghai Motor Show, is now available to order in the UK with sales starting on October 15.

The 2+2 luxury coupe will be offered with three engine, including two gasoline units and a turbo diesel, all fitted with BMW’s fuel-saving EfficientDynamics technology.

We were hoping to see the new BMW M6 at last month's Frankfurt Motor Show, but apparently, the Bavarian company has other plans for the presentation of its flagship two-door model that will be offered in both coupe and convertible derivatives.

Following recent pictures of the 2012 M6 Coupe, our spy shooters came up close and personal with a right-hand drive cabriolet model while testing in Europe.

First announced this summer, the BMW 650i is now available for order in the States with the option of the xDrive all-wheel drive system on both the Coupe and Convertible body styles.

The xDrive system will cost buyers an additional $3,000 lifting the MSRP of the 650i Coupe from $83,000 to $86,000, and the 650i Convertible from $90,500 to $93,500.

We were expecting to see the new M6 making its global premiere at this week's Frankfurt Motor Show, but apparently BMW has other plans set aside. Regardless of where the new M6's debut takes place, we should see the high-performance model in dealership by the summer of 2012.

The third iteration of the M6 in both Coupe and Convertible flavors will borrow the inner works of the latest M5 sports saloon, which means power will come from a 4.4-liter eight-cylinder engine supplemented by a pair of turbochargers and direct-injection technology.

The pride and joy of the Alpina stand in Frankfurt is the new B6 Bi-Turbo Cabrio based on the new BMW 650i Convertible.

The German tuning house has beaten its factory support to the punch with a high-performance version of the roofless 6-Series that boasts an uprated 4.4-liter twin-turbocharged V8 engine generating 507-horsepower and 700Nm (516.3 lb-ft) of peak torque between 3,000 and 4,750 rpm.

For more than four decades now, German tuning house Alpina has been modifying BMWs cars. The Bavarian luxury carmaker has a tight relationship with the tuner going as far distributing the high-performance models through its official network.

Alpina's newest creation is the B6 Bi-Turbo Cabrio based on the latest 6-Series Convertible, which will make its world premiere at the rapidly approaching Frankfurt auto show on September 13.