If you purchased the car from a dealership, the dealer collects it from you and pays it. If you purchased the car from a private owner, the county courthouse will collect it from you when you get it...
Probably the total price you paid for the vehicle - less the value of any trade multiplied by the tax percentage of your state: Example
$20,000 vehicle minus $5,000 trade value = $15,000 X 5% =...
Last time I checked, you did not have to pay sales tax in Florida if you gave someone a car. You had to pay a title transfer tax. That may have changed. It has changed a number of times.