Correct me if I'm wrong, but another way of finding out if you have LSD is by knowing what package was bought with the IS. If you have bought the LP package then you have LSD.
I did my homework before I bought my IS and this is what I found out. Basically, there were three packages offered for the IS and only one of them included LSD. To know if an IS has LSD just check if it has the ivory interior with the "beige" looking piping around the seats. Only the LP package has the ivory interior with piping, thus an IS with this interior will have LSD.
The Lexus Dealer in Hawaii and the Lexus Dealers in San Diego both offered these three packages, so I'm assuming that all the dealers offered them, too. I could be wrong if other dealers did it differently. However, I am very confident that this is how all the dealers sold their IS.
IS300_white