It’s no coincidence, but the cars we’d most like to drive are often track-only race cars. Case in point: the BMW Z4 GT3. Powered by an M3 GT2-derived 4.0-liter V-8 engine cranking out 480 horsepower, it’s the leanest and meanest member of the Z4 family.

This video snippet shows the upcoming Heffner-treated Audi R8 going from second to fourth gear on the freeway. As is typical with video footage, the car’s true power potential cannot really be seen on a screen. Its pull however, should be quite hectic in real life.

Russia’s Top Car isn’t the only tuner tampering around with the recently revealed, but not yet available, 2011 BMW 5-Series sedan. So is Racing Dynamics, otherwise known as RDSport in the USA. The Italian tuner that specializes on BMW products, has released a teaser photo (chop) and preliminary specs on the 535i R35 and the 550i R50S that will both receive a bevy of performance and styling mods.

The latest rumour in circulation is that the Nissan GT-R brand will get a hybrid powertrain in 2012 as a 2013 model year. According to Inside Line, the car would use the current 3.8-litre twin turbo V6 plus the battery powered electric drive powertrain in the 2009 Infiniti Essence Concept.

The folks over at M5Board.com and TeamSpeed.com have sent in these renderings of the upcoming BMW M5. Shown in the drawings is a mid-size four-door that many would be pleased to drive.

While we like the conceptual drawings very much, we do not think the next M5 will have such a race-ready look. Expect the front air intakes to be a bit less prominent, and the side sills to be less aggressive. After all, this is a car meant to appeal to executives, and will likely have a more conservative appearance than the drawings depict.