One problem related to wiring has been reported for the 2009 Volvo S40. The most recently reported issues are listed below.
Headlight wiring- made an attempt to change light bulbs for headlamps. Covering around electrical wiring harness which connect to headlight crumbled in my hands and electrical wiring is exposed. Worries that this may be potential fire hazard to my vehicle and myself. My vehicle was stationary in my driveway.