Lets not forget something else.
Many people dont have garages and/or driveways so they have to park their cars on the street some distance away from their dwelling. Can you say extension cord!
Now imagine a city like New York where many live in condo/apartment complexes and picture thousands of extension cords hanging out of windows to these electric cars.
Not very practical is it?
Yes, and imagine having to get to an important meeting in the morning only to find that someone else used your power for his car.