So sorry folks, we don't mean to cry wolf, but upon closer inspection we believe that this prototype is actually a revised F34 3 Series GT (Gran Touring).
With some of its rear camouflage removed, it revealed a sleeker hind roofline and revised rear, which gave it the appearance of a fastback/coupe-sedan, which we mistook for the 4 Series Gran Coupe. We apologize for the mistake.
The silver lining is that the 3 Series GT is looking sleeker/sportier than ever.
We've been looking at these spyshots for a couple of hours and compared them to previous 3 GT spyshots. As it turns out, this mule is different from earlier mules. The boot is a bit longer and seems to miss the retractable rear wing spoiler. The shape of the rear doors and rear side windows is very similar, yet not identical to earlier 3GT prototypes. The car appears to be sleeker and longer. That being said, we still don't think it's a 4 Gran Coupe for several reasons: This mule clearly is a hatchback and has a small third side window right behind the C-pillar. The ride height is too high, even for a 4-door coupe. This leaves us with two explanations possible. Either BMW has reworked the 3 GT which wouldn't be a first as the same happened to the 5-Series GT which started as the infamous RFK concept, or we're looking at a LWB 3-series GT. Again, whatever it is, it's most likely not the 4-series Gran Coupe.
Our resident insider Scott has now confirmed that it's actually the 3-series GT we're looking at. BMW hasn't revised the car but chose a very clever and tricky camouflage on earlier test mules.
Here's his full explanation: "It was perspex see-thru panels that was then layered with the camouflge sheets, the more 5er GT rear end was a vacumed plastic mold applied to the rear of the car and shrunk round the rear body before being covered in layers of BMW's patented camouflage , The rear shot shows the bulked out sides as does a previous shot where the tailgate is open and the panel overhangs from the edges.
The car has not been redesigned as it is too late to make any sheet-metal changes. It is very much indication of what you will get from BMW prototypes from now-on , even some use cannibalized parts from existing prototypes before they are destroyed like every BMW prototype including FEP cars.
The final 3er GT looks very much like this."
** Click on images for hi-resolution version **