BMW has announced two separate recalls to fix two separate potential fire risks.

One applies to 672,775 2006-2011 3-series cars (M3 included). In-dashboard wiring for climate control vents can overheat, which sometimes causes the wiring to melt, which sometimes causes the melted wiring to catch fire.

The other applies to 740,561 cars, specifically:

2008-2011 128i

2007-2011 328i, 328xi, 328i xDrive
2007-2011 525i, 525xi, 528i, 528xi, 530i, 530xi
2007-2011 X3 3.0si, X3 xDrive30i
2007-2011 X5 xDrive30i
2007-2011 Z4 3.0i, Z4 3.0si, Z4 sDrive30i

In this case, the heated PCV valve wiring can corrode and fail, which sometimes causes the valve to melt, which sometimes causes the melted valve to catch fire.

The parts required to repair these defects are on the way to dealers, who will begin performing the work on December 18th. There's a fair amount of overlap among cars covered by these two recalls so the total number of cars recalled is roughly one million.

You can check whether your car is affected at BMW's safety recall page.