A 2014 M3 test prototype resumed testing at the Nurburgring yesterday and the strip tease continued by way of a possible (or intended) camouflage malfunction.
Here's what we see.
By coincidence (?), the passenger side lower front bumper camouflage was flapped open during the test runs, revealing and confirming the air curtain vents on the F80. Whether the camouflage was peeled back to feed air to the air curtains for testing purposes, resulted from a camouflage malfunction, or was purposely peeled back to tease us, matters not. What's important is that we get the first clear look at the air curtain vent, which appears very large judging by the amount of space between the air curtain vent outline and the outer edge of the still camouflaged lower front bumper. Perhaps they are even large enough to have the added function of cooling the brakes. For a view of what the front end, including air curtains, may resemble once uncovered, we've reposted our render below.
With recent models, BMW has incorporated air curtain technology into front apron designs to optimize aerodynamics (see the 1M, 1 Series LCI, and 7 Series LCI). The air curtain vent reduces drag by forcing the air to flow more aerodynamically around the front wheels.