This information is from BMW insider Scott26. According to him, on the heels of the BMW X6's success, they have been investigating downsizing the range and bringing the Sport Activity
Coupe idea to the X3 range but with a bit more functional flair added and BMW would use the term
Sport Activity Sedan. Such a car would likely be dubbed the
X4. Internally, the car is known as the
X-Style. The same ideas that went into the X6 would be translated to the X4, namely a more sloping and sleek roofline as well as bulging fenders giving the car a wider and lower look compared to its X3 counterpart. The car would also get a two way hatch similar to the 5-Series GT.
This vehicle has not been approved for production yet, but the investigational concept seems to be in full swing!
**** The above picture is just a chassis test mule with an E91 body overlain on the chassis (designed for X3 development), and is not the X4!