Got front brakes done last weekend. When I went to test the car out, I noticed a loud hum when braking a little more aggressively. The mechanic said that I should give it about 50-70 km to break-in. Now, about 5 days and 500km later I'm still getting this noise. I thought ceramics were supposed to be quieter than metal. Should I give it more time or is there a definite problem and I need to go back to the mechanic asap?
PS Driving an '05 G6 base, 94000 km on it.