When doing replacement or upgrading on 1994 – 2018 BMW 540i xDrive adaptive capsule halogen headlamps HID lighting with without, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

Low Beam Headlight 1994 – 1995 9006
High Beam Headlight 1994 – 1995 9005
Front Fog Light 1994 9006
1995 H1
Back Up Light 1994 – 1995 1156
Brake 1994 – 1995 1156
Front Side Marker 1994 – 1995 12961
Front Turn Signal 1994 – 1995 P21/5W
License Plate 1994 – 1995 12844
Parking Light 1994 – 1995 1157
Rear Turn Signal 1994 1156
1995 P21W
Tail Light 1994 – 1995 12814
Center High Mount Stop Light 1994 – 1995 1156
Engine Compartment Light 1994 – 1995 578
Glove Box 1994 – 1995 DE3423
Trunk 1994 – 1995 6411
Low Beam Headlight 1997 – 2003 H7
High Beam Headlight 1997 – 2000 9005
2001 – 2003 H7
Front Fog Light 1997 – 2000 H7
2001 – 2003 H8
Back Up Light 1997 – 2003 1156
Brake 1997 – 2003 1156
Dome Light 2001 – 2003 578
1997 – 2000 6411
Front Side Marker 1997 – 2000 3157
Front Turn Signal 2001 3357NA
2002 – 2003 3457NA
License Plate 1997 – 2003 12844
Parking Light 1997 – 2000 3157
2001 – 2003 H6W
Rear Side Marker 1997 – 2000 12821
Rear Turn Signal 1997 – 2000 1156
Tail Light 1997 – 2000 12821
Front Inner Turn Signal 1997 – 2000 3157
Front Outer Turn Signal 1997 – 2000 12961
Center High Mount Stop Light 1997 – 2003 1156
Glove Box 1997 – 2003 DE3423
Stepwell 2001 – 2003 12844
1997 – 2000 DE3423
Trunk 1997 – 2003 6411
Low Beam Headlight 1997 – 2003 D2S
High Beam Headlight 1997 – 2000 9005
2001 – 2003 H7
Front Fog Light 1997 – 2000 H7
2001 – 2003 H8
Back Up Light 1997 – 2003 1156
Brake 1997 – 2003 1156
Dome Light 1997 – 2003 6411
Front Side Marker 1997 – 2000 3157
Front Turn Signal 2001 3357NA
2002 – 2003 3457NA
License Plate 1997 – 2003 12844
Parking Light 1997 – 2000 3157
2001 – 2003 H6W
Rear Side Marker 1997 – 2000 12821
Rear Turn Signal 1997 – 2000 1156
Tail Light 1997 – 2000 12821
Front Inner Turn Signal 1997 – 2000 3157
Front Outer Turn Signal 1997 – 2000 12961
Center High Mount Stop Light 1997 – 2003 1156
Glove Box 1997 – 2003 DE3423
Stepwell 2001 – 2003 12844
1997 – 2000 DE3423
Trunk 1997 – 2003 6411
Front Turn Signal 2017 – 2018 PY21W
Front Turn Signal 2017 – 2018 PY21W