I took my 13 WRX to the mountains today with my gf. On the way home, about 1/2 of the way, we heard a weird metal on metal sound. We both said "Glad that isn't our car" then sure enough about 5 minutes later we heard it again while turning into a parking lot and realized it was my car (most likely the steering) Looking over the car, I could not find anything wrong and all the fluids/belts were fine.
So I drive the car the rest of the way. It started getting louder and more frequent. It would do it while both driving and turning, but more so when turning. It also sounded like something was being pressurized. It got so bad that I pulled over for a few minutes. Then I decided to get going again because I was almost home. It started doing it again, then just completely stopped, drove 6 more miles, still no noise and hasn't done it since. I drove around my neighborhood for quite a while and it still didn't do it.
I'll also mention it was raining during this time. The car has 3,600 miles. Any advice on what this was?