When doing replacement or upgrading on 2004 – 2011 Mazda RX-8 with capsule halogen headlamps HID, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

Low Beam Headlight 2004 – 2011 H7
High Beam Headlight 2004 – 2011 H9
Front Fog Light 2009 – 2011 9006
2004 – 2008 H8/H11/H16
Back Up Light 2004 – 2008 7440
2009 – 2011 921
Brake 2004 – 2008 7443
Dome Light 2004 – 2011 DE3175
Front Side Marker 2009 – 2011 1157NA
2004 – 2008 194
Front Turn Signal 2009 – 2011 1157
2004 – 2008 7440NA
License Plate 2004 – 2011 12961
Parking Light 2009 – 2011 1157
2004 – 2008 12961
Rear Side Marker 2009 – 2011 12961
Rear Turn Signal 2004 – 2011 7440NA
Tail Light 2004 – 2008 7443
Center High Mount Stop Light 2004 – 2011 7440
Courtesy 2004 – 2011 12961
Map Light 2004 – 2011 12961
Trunk 2004 – 2011 194
Low Beam Headlight 2004 – 2011 D2S
High Beam Headlight 2004 – 2011 H9
Front Fog Light 2009 – 2011 9006
2004 – 2008 H8/H11/H16
Back Up Light 2004 – 2008 7440
2009 – 2011 921
Brake 2004 – 2008 7443
Dome Light 2004 – 2011 DE3175
Front Side Marker 2009 – 2011 1157NA
2004 – 2008 194
Front Turn Signal 2009 – 2011 1157
2004 – 2008 7440NA
License Plate 2004 – 2011 12961
Parking Light 2009 – 2011 1157
2004 – 2008 12961
Rear Side Marker 2009 – 2011 12961
Rear Turn Signal 2004 – 2011 7440NA
Tail Light 2004 – 2008 7443
Center High Mount Stop Light 2004 – 2011 7440
Courtesy 2004 – 2011 12961
Map Light 2004 – 2011 12961
Trunk 2004 – 2011 194