My 2012 has been doing this intermittently on warm days on a cold start. When I start it up I wear a squeaking noise that sounds like it's coming from behind the front left side of the dash that lasts for about 3 seconds or so then disappears, but as soon as I turn the air conditioning on it comes back for another few seconds then I don't hear it again. The car has 31k miles on it, and I know it's not a belt. Just my luck, anytime I take it to the dealer for them to hear it, it won't do it (go figure).

Does anyone have any ideas as to what it could be?

 

I was going to say a belt....maybe a pulley?

 

Could it be the tension of the belt? if its not the belt (Im guessing replaced) have you tried putting a little bit of lubricant (belt dressing) on the belt?

Another thing you could try is:

If the squeeking starts, open the hood, and check the if belt is 'jumping' or 'hopping' if it is chances are it could be a pully or more. I would start above and work my way down.