How much money do i need to save up for a used car?

I'm trying to buy a used car. My choices are Acura RSx, Dodge SRT-4, STi or WRX ( Depends ). Right now I Have 4k saved up , I know its not enough , but i want to have an idea of how i need, My dad is going to give me $2,000 for a down payment. I have a Job at McDonalds right now, but im looking to get a job at a bank. Thanks, IF you have any other awesome used cars I can buy please tell me. I want a car that is pretty fast and that i can trick out. Oh and manual transmission .