Electronic Parts Catalog?
//edit
Well after doing some searching in the United Kingdom, apparantly the Lexus IS 250 shares the same alternator as the Lexus IS 220d (130A). Which is weird, cause the IS-series (250 & 350) in America are sold with 180A alternators!! :S
They really think we Europeans are stupid.
Anyways here is some more information on the alternator:
http://www.toyodiy.com/parts/p_E_200...FSYW_1903.html
11/2006 LEXUS IS250/220D (ALE20L-AEFSYW)
SPO SED LHD 2ADFHV MTM