This is a DIY for a 03 - 08 Corolla S model with fog lights and switching to HID bulbs.
Bulb on a 05 Corolla S model is 9006
HID is 3000k for yellow
Remove the front part of the fender liner to make easy access .
This is a plug and play basically in my modification I put the ballast on top of the fog light housing to keep from getting wet a lot .
If the light does not work then switch the plug some times it can be plugged in reverse .