Brake rattle/creak noise
 

Just brought my '05 home from the dealer about 2-3 weeks ago and 2 nights ago after driving for 20 minutes I started noticing a rattling/creaking noise coming from the front. Not to be confused with any scraping, squeaking or grinding that may typically come from braking.

The next morning the noise had disappeared but after leaving work and driving for 30+ minutes the noise returned. This also happened a third time so it's clearly related to heat created from use.

So far I have only taken one wheel off to examine, as the sound seemed to be apparent in the front right. I did notice that it seems like there is some play between the caliper and pad to the point where if i move it manually with my hand, i can hear a slight clank with each tug. I have yet to confirm that none of the other calipers on the car do this but I don't feel like this extra room to move should be there so I'm going to consider this to be the issue for the time being.

There seems to be one slight warp in the rotor that I imagine is pushing the pad and caliper into each other at low speeds when braking after the rotor warms and expands.

It may not be the intended purpose for them as far as I know but i figure some brake pad shims would do the trick.

I just like validation and would like to see if this seems like a sound analysis to others or if perhaps anyone has had the same issue.

Also are there any reasons I should not use the shims? or any drawbacks to using them?

Should they go on all 4 or would it be ok to put them on one wheel if only the one had the extra room without having any pulling or other adverse effects?