BMW 5-Series

BMW's all-new 5-Series is prowling the streets of London! As testing of the new Mercedes E-Class rival ramps up, engineers at the German firm have really started to put in the test mileage – with these prototypes spied by an eagle-eyed reader in Knightsbridge.

As you can see, both the saloon and Touring versions have been spotted in convoy. The class-leading range is set to get a look that borrows its inspiration from the latest 5-Series Gran Turismo with a more upright front grille, less pronounced flame surfacing and a rakish roofline.

Inside, the cabin will be an evolution of the current car, altough there will be more space front and rear. Under the more conservative bodywork is expected to be tweaked versions of the current engine line-up. Entry-level models will get the 2.5-litre petrol straight-six, but a turbocharged 4.4-litre V8 is expected to replace the 5.0-litre V10 in the M5. Diesel fans will also have the choice of both 2.0-litre four-cylinder and 3.0-litre straight-six twin turocharged oil-burners.

Expect to see the showroom-ready version later this year with sales starting in early 2010.