After washing my 2004 RX330, the left front disc brake makes a metallic rubbing noise when the wheel is turned and the brake applied.

Anyone else, and any ideas what this is?

 

Both my RX300 and 330 have made squeaking noises when the brakes are applied while they are wet. Noise doesn't seem to change with wear / mileage. Doesn't always happen, either... a car wash makes it more likely, and a very humid, rainy or snowy day can do it, too.

I think it's due to high metallic content in the brake pads.

It's always stopped after things dry out. Using the brakes a couple of times generates enough heat to dry up the moisture.

 

That's typical for very wet brake. Nothing to worry about. Lightly apply the brake to dry the rotors.

If you are washing your Lexus at home, drive it around to dry up the rotors and brakes before putting it back to the garage.

 

Another thing you may notice is if washing at home, once the vehicle is dried and started, moved the ten feet into the garage and left overnight, is the rotors will get a thin coating of rust on the raw exposed rotor surface. this coating of rust can be heard making noise as the rotors turn when backing out. A couple applications of the brakes and the rotor surfaces are again smooth.