The equity in the car is the fair market value of the car (not your potential trade in value) minus the amount that you owe on the car. In a chapter 7 you will need to find an exemption available in Florida to protect the car against potential liquidation by a trustee.
You really can't afford NOT to have experienced bankruptcy counsel in your jurisdiction to help you navigate through the federal bankruptcy law and the uniquee exemptions available in Florida.
This answer is provided for informational purposes only. Actual legal advice can only be provided in an office consultation by an attorney licensed in your jurisdiction, with experience in the area of law in which your concern lies.
In South Florida, I have not heard of any objections against using the potential trade-in value instead of the fair market value.
Your car will be considered equity, and you will have to use exemptions to protect it. The amount of exemptions that you can use on that car depend on whether you are single or married, and whether you are claiming exemptions on other personal properties, and whether you are declaring homestead.
Otherwise, generally these things do not hurt your chances at filing chapter 7 bankruptcy.