Hey I have an IS300 also, except it is silver. It your car clearcoated, I heard black lexuses aren't clear coated. Anyway I think the problem is your washing method. Washing seems to be the number 1 source of swirls/micro scratches. You must use the 2 bucket method if you have a black car and get rid of that fake sheep skin wash mitt! Get a microfiber wash mitt or a 100% cotton chenille wash mitt. This will greatly reduce future swirls on your wonderful lexus . Have you tried meguiars scratch-X. I heard this is a really good product and I may pick up a tube for myself. Or better yet try 3M finesse it 2 (following carguy's instructions) and then follow up with some 3M smr. This got the swirls out of his black porsche. Good luck!