One problem related to trunk wiring has been reported for the 2010 BMW M3. The most recently reported issues are listed below.
The oem wiring insulation in the headlight housing has flaked off. The bare wires caused an electrical short when I replaced a light bulb. BMW says that the only repair is to replace the entire housing for $2100. This will need to be done on the other side eventually, as the insulation is deteriorating in that housing as well. I have read online that this is a common problem in many different models because of the type of wiring that was specified by BMW just does not hold up under higher temperatures. Knowing that it will be subject to higher temperatures in the engine compartment is a design oversight and will lead to dangerous malfunctions when operating the vehicle. It is just a matter of time.