There is a general feeling that women don't perform as good as men if this comes to buying cars. One does not have to pay for administrative charges, maintenance cost, and paperwork while dealing using a private owner. Apart from this, those who like imported or customized cars also prefer to approach private owners to avoid a lengthy legal process also to save some money.
It is important to mention that you simply don't have to become rude should you don't arrive at a contract with all the dealer. Make sure that you ask plenty of questions on anything and everything you're uncertain of.