I had this same issue. I replaced the headlight relay switch and it went away.Try to take apart the relay and clean the terminals it may just be corrosion.

 

it was where the windshield meets the dashboard, I guess when the car warmed up in the sun and the dashboard expanded a bit, it would barely rub against the windshield randomly making a squeaking/ticking sound.

Three years later, resolved. Fuuuuu. The dealership finally was able to locate the noise after keeping the car for two weeks. The solution was to shove a bit of foam between the dash and windshield. Not pretty, but quiet.