About 2 years ago i had new rotors and pads put on the front. I used thermo quite for both, about 2 weeks after doing that i started to notice a squeak sometimes when i would put on the brakes, took it back to the shop that did the work and they test drove it and could never reproduce the problem so they put it on the lift and checked every thing out could find nothing wrong. i know these guys personally and trust them. After about 2 years of this intermittent noise its getting a little old, any ideas on what i might try?