At 06:40 PM 11/10/2009, David Marshall wrote...
>First, show me where it says that 100W halogen bulbs are illegal.

The regulations (or more correctly, the SAE standards, which US
regulations incorporate by reference) are written in terms of light
output, not power input. 100W may, or may not, be against regulations.
Without measuring as installed in any specific lamp, there's no way to
know for sure.

CA regulations tend to follow the US ones. (although they do allow
e-code beam patterns). European regulations for HID headlamps require
automatic levelers, in recognition of their potential for blinding
other drivers.