The future saloon, codenamed G20, will replace the current F30 3 Series in 2018.
Previous G20 mules have been spotted testing at the Nürburgring (you can see one in our gallery), but this new prototype offers the best glimpse yet of what the final production model will look like and suggests it will share several features with the 2017 5 Series.
The biggest example of this shared design is the front bumper. It looks to feature the same three-intake layout as the next 5 Series, and while the temporary headlights are heavily camouflaged, the same overall light structure will most likely be incorporated.
Sources say the other changes to the G20 3 Series will give it tighter features and a harder-edged exterior.
Spy photographers caught a glimpse of the latest test mule's dashboard design, but it looks to be an adapted version of the current F30 3 Series dash, rather than previewing what's to come in the next-gen car.
Engines and driveline
The G20 is also expected to feature BMW’s turbocharged 1.5-litre three-cylinder engine at its entry-point, with turbocharged 2.0-litre four-cylinder petrol and diesel engines directly above it in the range.
More potent models, including the M3, will most likely still use turbocharged in-line six-cylinder units, but with gains in power and reductions in CO2 output.
When it arrives, the G20 range will have to conform to the EU’s next wave of emissions legislation, meaning it will be the first generation of 3 Series tasked with producing an average CO2 emissions output of less than 100g/km.
Like its predecessor, it’s expected to be available in both rear and four-wheel drive forms.
Most recently, BMW updated its current 3 Series GT model to bring it into line with the rest of the range, which was refreshed last year with a facelifted exterior and new engines.