One problem related to wiring has been reported for the 2007 BMW 3 Series. The most recently reported issues are listed below.
Wiring insulation cracking degrading leaving exposed bare wiring causing shorts and possible fire in headlight wiring harnesses, wires are stationary do not move. Insulation is craked and falling off wires. Noticed failure during bulb replacement. Made this complaint after reading about numerous other BMW owners noticing same fault.