Quote Originally Posted by McTaggart34 View Post
Bump for answer .. I wanna know too
Oh yeah
I found out why.
Once you do the install, you'll see why this was necessary.
The H1 bulb itself is really small, with no 'base' or 'seat.
The stock halogen H1 bulb that comes with these projectors have a separate piece which is the seat.
So the H1 bulb plugs into the 'seat' and the 'seat' is held down by the clip/headlight assembly.

This DIY, shows a way to make it work without the seat, meaning the H1 HID bulbs.
Because the HID bulbs are hard wired with a harness/pigtail design, you can not take the stock h1 bulb seat, and use it with the HID's