It is under the lower part of the dash under the trunk and gas door buttons.
There is no button on the 2004 SC 430. The button was introduced on the 2007 model. The 2002 through 2006 SC 430's require a procedure:
I would like to know if there will be a 2004 SC 430. If so, what changes will there be (compared to the current 2003 model on sale.) And when will it be available in the U.S.?
Is there any information on the 2004 SC 430?
When will it be released?
What changes will occur?
I've Google'd for information, but can't find anything reliable.