Just read a LA times article about it..
"In all the recalled cars, the battery is located in the trunk and there is a long battery cable from the battery to the fuse box, located between the glove compartment and the dash panel.
BMW said that both the connector at the end of the cable and the corresponding terminal on the fuse box are coated with tin.
The connection can degrade over time from the relative movements of the cable and the fuse box, which can eventually break the electric connection."
"BMW has known about the problem since July 2010 as a result of two field cases from the U.S. market involving the failure of the electrical system on a 3 Series vehicle when a customer experienced a "no-start" condition after it was parked. In October and December 2010, additional reports were received pertaining to the same problem.
It issued a service bulletin telling dealers how to fix the problem but has now decided to recall all 504,545 of the cars sold in the U.S.
BMW will notify owners, and dealers will replace the positive battery cable connector and secure it with an improved method, free of charge. The recall is expected to begin in March. Owners may call BMW for more information at (800) 525-7417 or email BMW."
That might explain why my car failed to start a few times.