1999 BMW 330

At low speeds front end makes noise WUM, WUM, WUM like brakes on a warped rotor. BMW tried to tell me it was bent rims and $2,400 to fix - RIGHT!
Had alignment done and all tires re-balanced by independent shop, and they didn't tell me my rims were bent. Again, low speed noise is significant and it mellows out a bit at highway speeds but still apparent. All tires are in spec and it isn't wear strips.
Any other ideas would be appreciated. Oh, I was also thinking wheel bearings?