you seem to be too new to this country, ..

buying a car isn't that simple that somebody tells you what to do and you can handle the dealers. i'd strongly recommend you to find a friend who has experience in buying cars and willing to help you. it's way easy to lose thousands when you are new to buy a car from dealers.

to answer your questions - yes you can negotiate the price; don't know "到12000 能買到嗎?"; no "還是隻能按dealer要的給?"