How to negotiate for a car price?

I've been trying to sell my BMW privately but no one wants it. I'm thinking of calling used car dealerships where they have a car I want. I want to trade in my 2009 BMW 328xi(80k miles) for a 2009 Honda Civic around 100k miles or lower. I just want a more reliable car. Anyways on blue book it says my trade in value is around 5k. The Honda I want is priced around 6 to 7k on blue book. How can I negotiate to get the car. There's a couple of used dealerships that have the Honda I want. I wouldn't mind leasing the remaing difference.

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