When doing replacement or upgrading on 1989 – 2007 BMW 525i 525iT 525xi capsule halogen headlamps HID with, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

Low Beam Headlight 1989 – 1995 9006
High Beam Headlight 1989 – 1995 9005
Front Fog Light 1991 – 1994 9006
1989 – 1990, 1995 H1
Back Up Light 1989 – 1995 1156
Brake 1989 – 1995 1156
Front Side Marker 1989 – 1995 12961
Front Turn Signal 1989 – 1995 P21/5W
License Plate 1989 – 1995 12844
Parking Light 1989 – 1995 1157
Rear Turn Signal 1989 – 1995 1156
Tail Light 1989 – 1995 12814
Center High Mount Stop Light 1989 – 1995 1156
Engine Compartment Light 1989 – 1995 578
Glove Box 1991 – 1995 DE3423
Trunk 1989 – 1995 6411
Low Beam Headlight 2001 – 2007 H7
High Beam Headlight 2001 – 2007 H7
Front Fog Light 2004 – 2007 9006
2001 – 2003 H8
Back Up Light 2001 – 2003 1156
2004 – 2007 921
Brake 2001 – 2007 1156
Dome Light 2001 – 2005 578
Front Side Marker 2004 – 2005 12961
Front Turn Signal 2001 – 2003 3357NA
2004 – 2005 PY21W
License Plate 2001 – 2003 12844
2004 – 2007 6418
Parking Light 2006 – 2007 12961
2004 – 2005 194
2001 – 2003 H6W
Rear Turn Signal 2006 – 2007 PY21W
Tail Light 2004 – 2007 1156
Front Inner Turn Signal 2006 – 2007 PY21W
Front Outer Turn Signal 2006 – 2007 12396NA
Center High Mount Stop Light 2001 – 2003 1156
Glove Box 2001 – 2007 DE3423
Interior Door 2006 – 2007 194
Stepwell 2001 – 2007 12844
Trunk 2001 – 2007 6411
Low Beam Headlight 2006 – 2007 D1S
2001 – 2005 D2S
High Beam Headlight 2001 – 2007 H7
Front Fog Light 2004 – 2007 9006
2001 – 2003 H8
Back Up Light 2001 – 2003 1156
2004 – 2007 921
Brake 2001 – 2007 1156
Dome Light 2001 – 2005 6411
Front Side Marker 2004 – 2005 12961
Front Turn Signal 2002 – 2003 3357NA
2001 3457NA
2004 – 2005 PY21W
License Plate 2001 – 2003 12844
2004 – 2007 6418
Parking Light 2004 – 2005 194
2001 – 2003 H6W
Rear Turn Signal 2006 – 2007 PY21W
Tail Light 2004 – 2007 1156
Front Inner Turn Signal 2006 – 2007 PY21W
Front Outer Turn Signal 2006 – 2007 12396NA
Center High Mount Stop Light 2001 – 2003 1156
Glove Box 2001 – 2007 DE3423
Interior Door 2006 – 2007 194
Stepwell 2001 – 2007 12844
Trunk 2001 – 2007 6411
Low Beam Headlight 1993 9006
High Beam Headlight 1993 9005
Front Fog Light 1993 9006
Back Up Light 1993 1156
Brake 1993 1156
Front Side Marker 1993 12961
Front Turn Signal 1993 P21/5W
License Plate 1993 12844
Parking Light 1993 1157
Rear Turn Signal 1993 1156
Tail Light 1993 12814
Center High Mount Stop Light 1993 1156
Engine Compartment Light 1993 578
Glove Box 1993 DE3423
Trunk 1993 6411
Low Beam Headlight 2006 – 2007 H7
High Beam Headlight 2006 – 2007 H7
Front Fog Light 2006 – 2007 9006
Back Up Light 2006 – 2007 921
Brake 2006 – 2007 1156
License Plate 2006 – 2007 6418
Parking Light 2006 – 2007 12961
Rear Turn Signal 2006 – 2007 PY21W
Tail Light 2006 – 2007 1156
Front Inner Turn Signal 2006 – 2007 PY21W
Front Outer Turn Signal 2006 – 2007 12396NA
Glove Box 2006 – 2007 DE3423
Interior Door 2006 – 2007 194
Stepwell 2006 – 2007 12844
Trunk 2006 – 2007 6411
Low Beam Headlight 2006 – 2007 D1S
High Beam Headlight 2006 – 2007 H7
Front Fog Light 2006 – 2007 9006
Back Up Light 2006 – 2007 921
Brake 2006 – 2007 1156
License Plate 2006 – 2007 6418
Rear Turn Signal 2006 – 2007 PY21W
Tail Light 2006 – 2007 1156
Front Inner Turn Signal 2006 – 2007 PY21W
Front Outer Turn Signal 2006 – 2007 12396NA
Glove Box 2006 – 2007 DE3423
Interior Door 2006 – 2007 194
Stepwell 2006 – 2007 12844
Trunk 2006 – 2007 6411