Planetary gearset to increase steering ratio?

[skrape]

Rhys Millen's GTO uses a planetary gearset to increase the steering ratio by 1.5:1... Does anybody know if this is a commercially available product, and where I can get one? (I'm betting it was an industrial gearbox of some sort that he sourced and adapted...)
This article is where I heard about it:
www.caranddriver.com/article.asp?section_id=17&article_id=8208&page_num ber=2

[drz]

Run a google search for "steering quickener". They are frequently used in dirt-oval racing.

[mk3mann]

get a custom billet gear at a cnc shop.

[tougeC]

how much do you think it would cost to get it from a cnc shop?