When doing replacement or upgrading on 2000 – 2009 Honda S2000, the bulb size guide is necessary for you to take the reference.
Jump to corresponding car model with the catalog bellow.

Low Beam Headlight2000 – 2009D2S
High Beam Headlight2000 – 2009H1
Back Up Light2000 – 20097440
Brake2000 – 20037443
Daytime Running Light2000 – 2009H1
Front Side Marker2004 – 200912396NA
2000 – 2003194
Front Turn Signal2000 – 20097440
License Plate2000 – 2009194
Parking Light2004 – 200912396NA
2000 – 2003168
Rear Side Marker2000 – 2003194
Rear Turn Signal2004 – 20097440
2000 – 2003PY21W
Tail Light2000 – 20037443
Map Light2000 – 2009DE3175
Trunk2000 – 2009168