I was told that there are only two packages available on the IS, the Sport and the Luxury. Basically the only difference between the two is that the Luxury is the tan interior with the heated seats/LSD. The sport is the Black interior without the heated seats/LSd. Can anyone confirm this for me? They say this is the wya they come from the factory? I would have hated to find this out now being that I own the Silver/Black int. without the LSD and Heatead seat options that I wanted??.