metalworker

I would have searched for an answer to this but the search on this forum forbids key words with less than 4 characters (what's up with that?) so XM can't be searched. I have a 2004 LS430. I have found an online source ( http://www.lexus-parts.com/partdetail.asp?...ubCategoryID=37 ) for the factory XM radio for $299. Has anyone installed this themselves? I have heard that Lexus charges about $200 for installation. By the way does anyone know of a better source for the radio?