I recently replaced my 2012 Audi Q5 brakes with after-market brakes. Right after, I started to hear some clanging noises coming from my front brakes. I immediately took it to a mechanic and they could not figure it out. So I decided to let the Audi professionals find out the issues. The left rotors were 0.14 under the minimal thickness so they came back at me with a bill to replace front brakes and rotors for $928.87 or a diagnostic fee of $170. My heart dropped, I gladly paid the diagnostic fee and got the hell out of there.
After picking up my car, my brakes were rattling even more. I then took my car to Mr. Brakes on Jones Blvd, they saw that the after-market brake pads I bought were crap. The after-market brakes were not secure and were moving back and forth, thus making the clanging noises. He also saw that the undercarriage was taken apart and not put back properly which was making all the extra noises. So I guess if you do not fix your car at Audi, they could care less if they put everything back together correctly. Once I replaced the brakes with OEM pads, my car works perfectly fine now for the fraction of the price.
Always get a 2nd opinion!