Two problems related to fuel hoses lines/piping and fittings have been reported for the 2004 BMW X3. The most recently reported issues are listed below.
Motorcycle: 2004 BMW r1150r, VIN ending in zf49715 defective fuel system part: fuel line quick release "connectors", part no. 13317659119. Plastic fuel line connector spontaneously fractured, spraying fuel on hot engine and exhaust pipe. Had there been a spark the motorcycle would have burned up in the street. BMW technician told me it was a common problem because after a year or so, the material, when exposed to fuel, became brittle. He was surprised there had not been a recall. I suspect there have been hundreds of unreported incidents with this part, some of which may have been tragic. I was stranded for quite a while, because at the time of the spontaneous rupture the engine had to be immediately shut off and the motorcycle pushed out of traffic and off the highway.
2004 BMW motorcycle 1150r VIN zf49715 defective fuel system part, fuel line quick release; connector "s",BMW part #13317659119. Plastic fuel line connector spontaneously fractured, spraying fuel on hot engine and exhaust pipe. Had there been a spark the motorcycle would have burned up in the street. A BMW technician said this was a common problem because after a year or so the material when exposed to fuel became brittle. Motorcycle was repaired.