The 2 simplest things I can suggest is that there:
-might be a bit of debris stuck.
-glazed due to overly light usage
I’d check for debris not only on pad area, but also stuck behind disc…
I’d also go out and give the brakes a real workout or a bedding in process. Pressing the brake pedal HARD each time. Brake from 30 and bring car *almost* to a stop, back up to 30 and repeat, then twice from 50 and then twice from 70. Don’t bring car to a complete rest during this process, so where you choose to do this requires some thought and planning. Then drive around normally for 10 to 15 minutes, again, not stopping the car and not being too gentle with brakes either.
Other thoughts: question bad pad alignment. Possibly due to rubber backing not being consistent thickness in one pad causing trailing edge of pad to contact disc first and creating high frequency vibration. Possibly also due to faulty caliper not internally distributing pressure to brake pistons properly.
A few things to check, going from simplest first.
// ’17 Nitrous Blue // Forged Alloys // Michelin Super Sports // Painted Calipers // Sync 3 // Lux Pack // Winter Pack // Black Gel Spoiler Badges // Blue Gel Wheel Inserts // GTechniq Liquid Crystal // GTechniq Alloy Armour // sold Jun ’18
Not had this problem, I am quite light on the brakes, in the past I have heard this problem linked to inferior pads as they have found substitute material for asbestos, have used copper slip on the sliders and back of the pad. Also heard from some that a saw blade cut across the pad eliminates this. But maybe not on this car as the pads aren’t cheap to replace.