When doing replacement or upgrading on 2006 – 2017 BMW 550i GT xDrive Adaptive 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 Headlight2006 – 2010 H7
High Beam Headlight2006 – 2010 H7
Front Fog Light2006 – 2007 9006
2008 – 2010 H8
Back Up Light2006 – 2010 921
Brake2006 – 2010 1156
Dome Light2008 – 2010 194
Front Turn Signal2008 – 2010 3457NA
License Plate2008 – 2010 12844
2006 – 2007 6418
Parking Light2006 – 2007 12961
2008 – 2010 3357NA
Rear Turn Signal2006 – 2007 PY21W
Tail Light2006 – 2007 1156
Front Inner Turn Signal2006 – 2007 PY21W
Front Outer Turn Signal2006 – 2007 12396NA
Glove Box2006 – 2010 DE3423
Interior Door2006 – 2007 194
Map Light2008 – 2010 12961
Rear Reading Light2008 – 2010 194
Stepwell2006 – 2010 12844
Trunk2006 – 2010 6411
Low Beam Headlight2006 – 2007 D1S
High Beam Headlight2006 – 2007 H7
High Beam and Low Beam Headlight2008 – 2010, 2014 – 2016 D1S
Front Fog Light2006 – 2007 9006
2008 – 2010 H8
Back Up Light2006 – 2010, 2014 – 2016 921
Brake2006 – 2010 1156
Daytime Running Light2008 – 2010 H8
Dome Light2008 – 2010, 2014 – 2016 194
Front Turn Signal2008 – 2010 3457NA
2014 – 2016 PY24NA
License Plate2008 – 2010 12844
2006 – 2007 6418
Parking Light2008 – 2010 3357NA
Rear Turn Signal2006 – 2007 PY21W
Tail Light2006 – 2007 1156
Front Inner Turn Signal2006 – 2007 PY21W
Front Outer Turn Signal2006 – 2007 12396NA
Glove Box2006 – 2010 DE3423
Interior Door2006 – 2007, 2014 – 2016 194
Map Light2008 – 2010, 2014 – 2016 12961
Rear Reading Light2008 – 2010 194
Stepwell2006 – 2010 12844
Trunk2006 – 2010, 2014 – 2016 6411
High Beam and Low Beam Headlight2011 – 2013 D1S
Front Fog Light2011 – 2013 H8
Back Up Light2011 – 2016 921
Brake2011 – 2016 H21W
Dome Light2011 – 2016 194
Front Turn Signal2011 – 2013 PY24NA
Interior Door2011 – 2016 194
Map Light2011 – 2016 12961
Trunk2011 – 2016 6411
High Beam and Low Beam Headlight2012 – 2015 D1S
Back Up Light2012 – 2015 PW16WHTR
Brake2012 – 2015 PW24WHTR
Dome Light2012 – 2015 194
Luggage Compartment2012 – 2015 194
Interior Door2012 – 2015 194
Map Light2012 – 2015 12961
Low Beam Headlight2010 – 2011 D1S
High Beam Headlight2010 – 2011 H7
Front Fog Light2010 – 2011 H8
Back Up Light2010 – 2011 921
Dome Light2010 – 2011 194
Front Turn Signal2010 – 2011 PY24NA
License Plate2010 – 2011 6418
Luggage Compartment2010 – 2011 6411
Courtesy2010 – 2011 194
Map Light2010 – 2011 12961
High Beam and Low Beam Headlight2012 – 2017 D1S
Back Up Light2012 – 2017 PW16WHTR
Brake2012 – 2017 PW24WHTR
Dome Light2012 – 2017 194
Luggage Compartment2012 – 2017 194
Interior Door2012 – 2017 194
Map Light2012 – 2017 12961
Low Beam Headlight2010 – 2011 D1S
High Beam Headlight2010 – 2011 H7
Front Fog Light2010 – 2011 H8
Back Up Light2010 – 2011 921
Dome Light2010 – 2011 194
Front Turn Signal2010 – 2011 PY24NA
License Plate2010 – 2011 6418
Luggage Compartment2010 – 2011 6411
Courtesy2010 – 2011 194
Map Light2010 – 2011 12961
High Beam and Low Beam Headlight2014 – 2016 D1S
Back Up Light2014 – 2016 921
Dome Light2014 – 2016 194
Front Turn Signal2014 – 2016 PY24NA
Interior Door2014 – 2016 194
Map Light2014 – 2016 12961
Trunk2014 – 2016 6411
High Beam and Low Beam Headlight2011 – 2013 D1S
Front Fog Light2011 – 2013 H8
Back Up Light2011 – 2016 921
Brake2011 – 2016 H21W
Dome Light2011 – 2016 194
Front Turn Signal2011 – 2013 PY24NA
Interior Door2011 – 2016 194
Map Light2011 – 2016 12961
Trunk2011 – 2016 6411