One problem related to gas recirculation valve (egr valve) has been reported for the 2007 BMW 328. The most recently reported issues are listed below.
Just finished driving about 10 miles from home to work, about 70 degrees-f outside, sunny, good weather around 11am. Did not operate air conditioner, heater or vent fan. Car seemed to drive fine, no strange noises. Had no recent major repairs. We are second owners of certified pre-owned BMW, have had vehicle for the past 7 years and driven about 50k miles since purchase. After arriving at workplace, stopped at workplace parking lot with engine idling for a few seconds to wait for parking gate to open. However, began seeing white smoke coming out of driver's side of engine hood. Tried to reverse the vehicle out to the street and moved about 10ft before engine shut off and would not restart. Within 15-30 seconds a plume of fire erupted out of the front hood through the grill. Within 3 minutes entire car was engulfed in flames and its proximity to other cars in the lot caused fire damage to 4 other vehicles. Car was a total loss including all possessions within it. Electronic locks quit working as soon as fire started.