Bulb Type: D2R (I believe D2S works fine according to what I've read).
These cost a fortune from Toyota (I believe about $175 USD each).
They are just a D2R bulb which can be found much cheaper anywhere else.

I have heard of some people having to adjust or hack the plastic tab on the bulb to make it fit the Toyota headlamp.

Below is a helpful guide on accessing and replacing this D2R bulb since it's not as straight forward as some other cars:

http://www.clublexus.com/forums/gs-s...placement.html