On the inside of my windshield where defrost air meets glass there is a mist type film on it like a fine oil spray could this be from turbo leaking and defrost air sucking it in or something else?

This almost always means the heater core is leaking. The residue is antifreeze, which does not evaporate. If you've noticed a lot of steaming up of the glass while using the defroster or very poor performance, this is why. The steaming leak (it can be very small) carries the antifreeze with it, condensing on the glass and leaving the residue. The heater core has to be replaced.

Thank you will have dealer check it :)