Recently my 06 Mazda 6 5door 3.0 started a loud front noise creaking, making a rubbery, metallic/popping noise when turning, braking, and going over bumps. I suspected several front suspension problems, but started with the brakes. The front brake caliper mount bolts needed to be lubricated with grease because the calipers self align with the rotor on these bolts. Mine were semi dry, with old gummed up grease. Cleaning and re-lubricating the caliper bolts solved a problem that I thought was going to be real expensive to fix. Thought I would post this to help anyone that is having this problem.

Edit: What I am calling caliper mount bolts are actually called caliper guide pins. The manual says that there are two guide pins pr wheel on 2006 and later models. On 2005 models or earlier lubricate the lower mounting pin and the upper bolt with high temperature grease.