Squeak/Chirp When Turning - Diagnosis?

I've been hearing a squeak when I turn the car to the right (wheel at about a 45 degree angle). At first I thought it was brake pad warning tab related, but when I had my suspension work done they said the pads and rotors looked good.

The sound has now recently started to occur while driving straight as well as the usual right turn (sound is never present with a left hand turn), which makes me think that it must be pad related. The sound appears to be coming from the left of the car and is about once every revolution of the wheel (speeds up with MPH/KH). Wheels and brake system are all stock on a 2001 320.
I don't want to take it in to the dealer since it could be something simple.

I've also searched for topics on the forum and have only seen diagnoses of similar sounds as brake pads squeaking. Should I ignore the shop's assessment of my brakes being ok and lube her up with brake grease?

I know it never hurts to use plenty of lube. "That's what she said."