I stumbled across this guide:

Low Beam Headlight Bulb Size: 9003/HB2
High Beam Headlamp Light Bulb Size: 9003/HB2
Parking Light Bulb Size: 168
Front Turn Signal Light Bulb Size: 7440
Rear Turn Signal Light Bulb Size: 992 (7440A)
Tail Light Bulb Size: 7443
Stop Light Bulb Size: 7443
High Mount Stop Light Bulb Size: LED
License Plate Light Bulb Size: 168
Back Up Light Bulb Size: 921
Front Sidemarker Light Bulb Size: 168
Dome Light Bulb Size: DE3175
Trunk/Cargo Area Light Bulb Size: DE3022

At this site
http://www.modifiedlife.com/2008-scion-xd-car-light-bulb-size-guide/

Here's a slightly biased guide from Sylvania (promotes their products, lol)

2008 SCION xD

High & low beam headlamp
9003/HB2
9003SU Silverstar ULTRA for Ultra Night Vision - The Whitest and Brightest Halogen
9003ST Silverstar High Performance Lighting: The Whiter and Brighter Halogen
9003XV XtraVision Halogen - The Brighter Light
9003CB Cool Blue Halogen - The Whiter Light

Parking light
168
168LL Long Life Upgrade: Up to twice the life of the standard lamp

Front turn signal
7440
7440LL Long Life Upgrade: Up to twice the life of the standard lamp

Rear turn signal
992 (7440A)

Tail light
7443

Stop light
7443

High mount stop light
LED

License plate
168
168LL Long Life Upgrade: Up to twice the life of the standard lamp

Back up light
921
921LL Long Life Upgrade: Up to twice the life of the standard lamp

Front sidemarker
168
168LL Long Life Upgrade: Up to twice the life of the standard lamp

Dome light
DE3175
DE3175LL Long Life Upgrade: Up to twice the life of the standard lamp
7443LL Long Life Upgrade: Up to twice the life of the standard lamp

Trunk/Cargo area
DE3022

link: http://www.sylvania.com/sylvania/Templates/Detail/AutoReplacement_Start.aspx?NRMODE=Published&NRORIGINALURL=%2fConsumerProducts%2fAutomotiveLighting%2fLampReplacementGuide%2f&NRNODEGUID={7A0B9B8E-E8D8-4E08-97CD-220CA5447557}&NRCACHEHINT=NoModifyGuest

Most vehicles are listed there :)

NICE !!!

GREAT POST !!!

This should go to the tech section.

Now, has anyone replaced their dim dome light bulbs with one of those 20 LED strips from


http://www.oznium.com/led-dome


And I wonder, do they fit as well in a xD as they do in a xB?