maybe I just noticed this but when I drive my C4S during heavy rain my brake pedal feel/feedback becomes soft and the brakes become noisy. I think its from the rotors oxidizing but I've never experienced anything like this before. Maybe I just need some new brake pads (25000 miles) I don't know. Any ideas here?

 

Your rotors are likely covered with a thin film of water, takes a second to dry/take it off.

You might also need a brake fluid change.

 

It's perfectly normal that your brakes won't work as well when they're wet. But noisy? The only time that usually happens is when you first drive them after the rotors have rusted slightly, but it only takes one highway stop on an exit ramp to get rid of that surface rust. And it's usually barely noticeable anyway.

At 25k miles you're probably close to due for some new pads, and if you're still running the original fluid, you're well overdue for a flush and replacement.