When doing replacement or upgrading on 2012 – 2018 Fiat 500 500L 500X Hatchback, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

High Beam and Low Beam Headlight2012 – 2018 9012
Front Fog Light2012 – 2018 H8/H11/H16
Back Up Light2012 – 2018 921
Brake2012 – 2018 1157
Daytime Running Light2012 – 2018 7443
Dome Light2012 – 2018 6418
Front Side Marker2012 – 2018 12256
Front Turn Signal2012 – 2018 7440NA
Parking Light2012 – 2018 7443
Rear Side Marker2012 – 2018 12256
Rear Turn Signal2012 – 2018 PY21W
Tail Light2012 – 2018 P21/5W
Luggage Compartment2012 – 2018 194
Center High Mount Stop Light2012 – 2018 194
High Beam and Low Beam Headlight2014 – 2018 9012
Front Fog Light2014 – 2018 H8/H11/H16
Back Up Light2014 – 2018 921
Brake2014 – 2018 1157
Daytime Running Light2014 – 2018 7443
Dome Light2014 – 2018 12854
Front Turn Signal2014 – 2018 7440NA
License Plate2014 – 2018 12961
Parking Light2014 – 2018 7443
Rear Turn Signal2014 – 2018 1156
Tail Light2014 – 2017 1157
2018 P21/5W
Luggage Compartment2014 – 2018 DE3423
Courtesy2014 – 2018 12961
Glove Box2014 – 2018 DE3423
Rear Fog Light2014 – 2018 921
High Beam and Low Beam Headlight2016 – 2018 9012
Front Fog Light2016 – 2018 H8
Back Up Light2016 – 2018 1156
Brake2016 – 2018 1156
Daytime Running Light2016 – 2018 1157
Dome Light2016 – 2018 DE3423
Front Side Marker2016 – 2018 12396NA
Front Turn Signal2016 – 2018 7440NA
License Plate2016 – 2018 12961
Parking Light2016 – 2018 1157
Rear Turn Signal2016 – 2018 1156
Tail Light2016 – 2018 1156
Luggage Compartment2016 – 2018 DE3423
Courtesy2016 – 2018 12844
Glove Box2016 – 2018 12961
Map Light2016 – 2018 12961