We had the heavy brake residue problem and took it to the dealer. They replaced the brakes with new ones, and said, no charge, that is a known problem with the 06 IS 350 and is covered under warranty. No problem now.
I have just replaced the stock Bridgstone Potenza tires at 42K, and that was because of a toe-in issue. The new tires are Michelin Pilots. I hope to get at least another 40-45K out of them.