Answer: Water vapor from the air freezes on the glass
Step-by-step explanation:
I believe this one is correct because, for water to already be on the car it would of had to rain and clearly as state there isnt any rain. If Moisture comes from inside the car and freezes, then the windshield inside of the car would be icy. Hydrogen and oxygen in the air combine and form water, and it freezes isnt likely to be the answer but it definitely would be the second best.