One problem related to wiring has been reported for the 2007 BMW 525. The most recently reported issues are listed below.
Headlight wiring insulation rot lead to failed high and low beams on driver side and intermittent failures of both beams on passenger side. See photo for exampole of disintegrated wiring on driver high beam wiring harness. Only known option is to buy a complete new headlight assembly ($1250+ per side) or attempt diy. This problem is well-known and has long been reported by other BMW e60 (5 series 2004-2010) owners at bimmerfest. Com and 5sriest. Net. . Read more...