The wife totalled her 2004 Tahoe LT in a traffic accident and we bought a 2004 Tahoe LS as the replacement. The 2004 Tahoe LS doesn't have Onstar. There's no Onstar buttons on the inside rear view mirror and no Onstar antenna. We had Onstar on the Tahoe she totalled. Does anybody know why one vehicle would have Onstar and the other wouldn't besides the obvious of one being an LT and the other being an LS? Both vehicles have/had an in-service date of June 2004. Thanks.