I change the oil and wash it every year, whether it needs it or not! Actually, I do drive it occasionally just to keep it lubricated and check the tires as other people mentioned.
On a side note, a friend was complaining about their car and the harsh weather we just had. I told them I cleaned the snow off the car and put it in the garage to stay clean in case I needed it this winter. I loved the look on his face!

Marc