When doing replacement or upgrading on 2006 – 2018 Mazda MX-5 Miata with capsule daytime halogen headlamps HID lamps LED running 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 2006 – 2015 H7
High Beam Headlight 2006 – 2015 H9
Front Fog Light 2006 – 2015 H8/H11/H16
Back Up Light 2006 – 2015 921
Brake 2006 – 2015 7443
Dome Light 2006 – 2015 DE3175
Front Side Marker 2006 – 2015 194
Front Turn Signal 2006 – 2008 7440NA
2009 – 2015 7444NA
License Plate 2006 – 2008 12961
2009 – 2015 194
Parking Light 2006 – 2008 12961
2009 – 2015 7443NA
Rear Turn Signal 2006 – 2015 7440NA
Tail Light 2006 – 2015 7443
Trunk 2009 – 2015 DE3175
Low Beam Headlight 2006 – 2015 D2S
High Beam Headlight 2006 – 2015 H9
Front Fog Light 2006 – 2015 H8/H11/H16
Back Up Light 2006 – 2015 921
Brake 2006 – 2015 7443
Dome Light 2006 – 2015 DE3175
Front Side Marker 2006 – 2015 194
Front Turn Signal 2006 – 2008 7440NA
2009 – 2015 7444NA
License Plate 2006 – 2008 12961
2009 – 2015 194
Parking Light 2006 – 2008 12961
2009 – 2015 7443NA
Rear Turn Signal 2006 – 2015 7440NA
Tail Light 2006 – 2015 7443
Trunk 2009 – 2015 DE3175
Back Up Light 2016 – 2018 7440
Daytime Running Light 2016 – 2018 7440
Dome Light 2016 – 2018 DE3175
Front Side Marker 2016 – 2018 194
Front Turn Signal 2016 – 2018 7444NA
License Plate 2016 – 2018 194
Rear Side Marker 2016 – 2018 194
Rear Turn Signal 2016 – 2018 7440NA
Trunk 2016 – 2018 DE3175