Brakes squeeling

[Beauzapp]

I have a 2010 370z that is in wonderful condition. The only problem I have is the brakes squeal like crazy first thing in the morning when I am backing out of the garage.

background...I have Sport Brakes.... I live in Florida, I have 45K mileage, new pads where put on the car by a Nissan dealer at 43K mileage, the rotors are in good shape and do not have any high or low spots, the car stops straight and does not pull, the squealing noise is very loud, the whole neighborhood can hear it, it goes away for the most part once I drive the car........

My brake shop says the squealing is caused by the humidity here in Florida and metal shavings in the pads....that does not make any sense...any ideas on how to make the squealing go away?

Thanks Matt