What can happen to me if I cannot pay a final court judgment to collect a $6000 credit card debt? The only thing I have is a 2013 car, no money.

I'm assuming that the debt was yours alone and not on a joint debt with your wife.  There are various collection mechanisms available to your creditor, including garnishing any wages or other income your receive until the debt if paid in full, seizing any non-exempt assets you have now (not sure whether you car is exempt in Fla., in NY it's only partly exempt) or in the future (for 20 years in NY, but may be a different time period in  Fla) and perhaps forcing you into an involuntary bankruptcy where the court would oversee your finances.