Porsche 911 spy shots

If we learned nothing else from our recent frolic through Porsche's secret museum, it's that the automaker goes to incredible lengths to disguise future products during initial testing. Just as a number of cars in that Stuttgart bunker hid the true identity of developmental mules (like the Audi-V8-powered 911), such could very well be the case with these spy shots showing what, on the surface, appears to be simply a facelifted 991 911 Cabriolet.

Similar to what we saw last month on a 911 coupe, this Cabriolet has obvious styling modifications made to the front and rear fascias suggesting that the 911's still-fresh appearance is already set to get a few tweaks. The big news here is at the rear of the car. The additional vents on the lower edge of the fascia and the mocked-up vent above the engine leads our spy photographer to believe that a new engine could be tucked under the body work – likely a smaller-displacement, turbocharged flat-six focusing more on improving fuel efficiency and reducing exhaust emissions rather than performance.

We last heard rumblings of such a detuned 911 back in August, but could this be our first look at said new model? Have a look for yourself, and let us know what you think – either about this mule specifically or the idea of a "green" 911, in Comments below.