Brakes are designed to start to make a sort of metal on metal grinding when they are close to requiring a change, if when the window is down you don't hear that your prpbrably good, however that's not the only sign you may need new pads even if you don't hear this sign or don't need them if you do.
You can see the pad through the wheel, you should have at least 1/4 inch minimum of good pad
My 2011 cruze ltz 1.4T has 48k on the odo and has around 15-20k miles left on the pads, and yes the first few presses on the pads after rain is superficial rust adhering to the ceramic pads a little better that the fine metal rotor, you wear that down with only a couple turns of the wheel
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You can see the pad through the wheel, you should have at least 1/4 inch minimum of good pad

My 2011 cruze ltz 1.4T has 48k on the odo and has around 15-20k miles left on the pads, and yes the first few presses on the pads after rain is superficial rust adhering to the ceramic pads a little better that the fine metal rotor, you wear that down with only a couple turns of the wheel
Sent from my SM-G930V using Tapatalk