Audi Repair Questions? Ask a Mechanic for Answers ASAP
As long as the mechanic didn't overlook anything then I think it is very likely that some dirt or a small rock got caught between the brake pad and rotor. I don't know which wheels you have on your TT or where you live but we see this on occasion in Colorado. Mostly when it has been raining or on cars that drive a lot on dirt roads we see this happen. If something got pulled in while driving and the noise started then the debris likely got pushed out when you reversed but perhaps another piece got pulled in on the front side. Eventually they will fall out or grind up and disappear. If your wheels are fairly open and you can easily see the brake rotor then you can take your car to the carwash and used the wash wand to spray out whatever debris there might be around the brake pads and calipers. I suspect this is all that happened and washing the wheels and brakes will keep them quiet. If not then let me know and I would be happy to dig into it a little deeper.
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