We just posted our first drive of the 2014 BMW 435i yesterday, but for those wanting even more power from this stylish coupe, help is on the way. From the sounds of it, BMW will be showing off a production-ready concept previewing the M4 next month at the Pebble Beach Concours d'Elegance, but until then, we have some new spy shots of the performance coupe being tested at the Nürburgring, along with its four-door counterpart, the M3.
Despite all the camouflage, it doesn't take much imagination to picture what both cars will look like, since we can clearly see the more aggressive front fascia and beefier brake setup. One interesting element we see on both cars is a double bubble roof that is almost certainly made from carbon fiber. Based on our report earlier, both the M4 Coupe and M3 Sedan are expected to debut at the 2014 Detroit Auto Show.