For the 2003 Subaru Impreza, both the low-beam and high-beam headlights use a 9007 bulb. The supplied fitment data does not identify a separate projector or non-projector headlight variation, so confirm the original bulb before ordering.
- Fog lights: Use H3 or H3C; compare the installed bulb and socket to determine the correct option.
- Front turn signals: 1156.
- Brake lights: Compare the original bulb, as fitment may be 7440R or 7443R.
- Center stop light: 921, with 912 listed for wagon models.
- Reverse lights: 7440. The tail light uses 7443R, while the rear turn signal uses 7507.
- Small exterior bulbs: 168 or 917 for the parking and license-plate lights; front and rear side markers use 168NA.
- Interior bulbs: The dome light uses DE3175. Map lights use 168 or 917. The ash light may use 2721 or 74, so compare the original.
- Trunk light: 921, with 912 listed for sedan models.