Not long ago our spy photographers managed to capture images of a BMW Z5 test mule getting a beatdown in the harsh snow-covered terrain of northern Sweden. Set to replace the current Z4, the Z5 is BMW's version of the new sports car platform jointly developed with Toyota. It's been long rumored that Toyota's version will become a new Supra. Anyway, progress is happening and, according to a new report from Automobile Magazine, the Z5 is going to be a soft top convertible only. There will be no coupe version. Instead, that coupe will be the Toyota.

Although both BMW and Toyota have remained mum on what engines will be available for each respective car, word has it that BMW will opt for a 450-hp inline-six in the top-of-the-line Z5 M. Toyota's best Supra trim will be powered by a twin-turbocharged V6 developed in Japan. Both cars will be underpinned by the same aluminum and carbon fiber chassis that will cut down on overall weight. For lower trim Z5s, expect base power to be sourced from a range of four- and six-cylinder engines which, if appropriately powered, could better place the Z5 in Porsche Boxster competition territory. Also said to be in development is a Z5 hybrid, but we figure the four-cylinder version will end up being the volume seller.