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 Headlight 2012 – 2018 9012
Front Fog Light 2012 – 2018 H8/H11/H16
Back Up Light 2012 – 2018 921
Brake 2012 – 2018 1157
Daytime Running Light 2012 – 2018 7443
Dome Light 2012 – 2018 6418
Front Side Marker 2012 – 2018 12256
Front Turn Signal 2012 – 2018 7440NA
Parking Light 2012 – 2018 7443
Rear Side Marker 2012 – 2018 12256
Rear Turn Signal 2012 – 2018 PY21W
Tail Light 2012 – 2018 P21/5W
Luggage Compartment 2012 – 2018 194
Center High Mount Stop Light 2012 – 2018 194
High Beam and Low Beam Headlight 2014 – 2018 9012
Front Fog Light 2014 – 2018 H8/H11/H16
Back Up Light 2014 – 2018 921
Brake 2014 – 2018 1157
Daytime Running Light 2014 – 2018 7443
Dome Light 2014 – 2018 12854
Front Turn Signal 2014 – 2018 7440NA
License Plate 2014 – 2018 12961
Parking Light 2014 – 2018 7443
Rear Turn Signal 2014 – 2018 1156
Tail Light 2014 – 2017 1157
2018 P21/5W
Luggage Compartment 2014 – 2018 DE3423
Courtesy 2014 – 2018 12961
Glove Box 2014 – 2018 DE3423
Rear Fog Light 2014 – 2018 921
High Beam and Low Beam Headlight 2016 – 2018 9012
Front Fog Light 2016 – 2018 H8
Back Up Light 2016 – 2018 1156
Brake 2016 – 2018 1156
Daytime Running Light 2016 – 2018 1157
Dome Light 2016 – 2018 DE3423
Front Side Marker 2016 – 2018 12396NA
Front Turn Signal 2016 – 2018 7440NA
License Plate 2016 – 2018 12961
Parking Light 2016 – 2018 1157
Rear Turn Signal 2016 – 2018 1156
Tail Light 2016 – 2018 1156
Luggage Compartment 2016 – 2018 DE3423
Courtesy 2016 – 2018 12844
Glove Box 2016 – 2018 12961
Map Light 2016 – 2018 12961