One problem related to trunk wiring has been reported for the 2008 BMW 328. The most recently reported issues are listed below.
Drove my 2008 BMW 328xi sedan to work site about 54 miles away from my home town with no issues. After a long day of work, got into car and started engine. Noticed smoking coming out of engine compartment. Open hood and noticed small fire coming from underneath the intake manifold near some wiring. Small but still on fire. Put out fire by blowing on. Car started up fine with no error codes. Tried starting again, same result. A electrical short with smoke and flame. I put it out again with water. Had the car towed to my local BMW dealer to have a repair. BMW dealer checked it out and said that the car had a electrical wiring harness fire and no other issues. They said it would cost $2700 dollars to repair and was not covered under BMW's warranty. This car has 29000 miles on it. How in the world is this not covered by their warranty. This was a vehicle fire! it is not normal for a car to catch on fire by itself is it not?.