I baught my City 2001 though ad in newspaper. It is a great way to buy cars. And ofcourse one does not get to listen to those all the time lying salesmen who would sell you anything as long as there is commission to be earned.
Moreover the price of cars baught this way is generally lower than the price of same car at the dealer plus ofcourse the commission.
When I was surveying to buy my car, generally there was a difference of Rs. 50,000/- or more that was being demanded by the dealer.