Try Wesco Track & Tire on Sepulveda Blvd. in North Hills. They do chrome exchanges for all sorts of cars and they can probably get you chrome centers for your new chromes. (If you exchanged wheels at your Lexus dealer, please don't ask the Wesco guys what you could have paid if you'd done the swap with them. It'll break your heart.)
It's right around the corner from Galpin Ford at the Roscoe exit off the 405.
