The UK magazine all about the car has some photoshopped shots of what they're claiming is how the 2009 5-series, and 2010 M5, are shaping up as they move into the sixth-generation of the four-door sedan. Supposedly the new version will be "less provocative in design" than the current incarnation and despite what car mag's claiming is an increase in size, the '09 model will use "more exotic, lighter materials" to give it a lower weight than the current model. As far as engines go, they claim to have the full deets, but in order to increase fuel economy, the engines should include something called "urea injection" which we hope means a reduction in Nitrogen Oxides in emissions, and doesn't mean they'll be shooting urine into the engine.
Secret New Cars: BMW 5-series [carmagazine.co.uk via AutoBlog]
Related:
Spy Photos: BMW M5 Touring? [internal]