I think you should check your valve cover gasket (I think that's what it's called).
I had the same oil smell coming out of the AC Vents for a few months. I thought that was weird but couldn't figure out what it was.
Then one day smoke came out of the engine bay too. Panicked as hell, so I just drove to the dealer and tell them to find out what's wrong.
They told me it was just the valve cover gasket.
Save yourself some money and try that first and do it yourself. I really wished I had done it myself and save a couple hundred $$$
Here's a link
http://www.focushacks.com/index.php?modid=83
Let us know if that fixes it