bxgurl, yes, that is something I thought about. But, I was right inside the house and did not hear any truck or noise. I only heard cars passing by (one of which mush have been mine!). Also, I don-t really thing a truck that can carry a car would fit in the small street where my car was.
All makes me think somebody had a copy of my key, or something that could serve as a key. Police seems to agree with this, and I still don't understand how this is possible unless a car dealer is involved. I can't eve remember any other occasion when I gave my key to anybody...