If you but from a licensed dealer, he is required to collect sales tax from you to remit to the state, unless you are a non-res, like your Fl deal, in which case he will send in record of the out-of-state tax exempt sale instead of the tax he collected from you. Then your home state collects the tax. When you but from an individual, no matter the state, it's up to you to pay the sales tax at the BMV when you transfer title and register it. It is a scam that the states will collect sales tax on the same car everytime it is sold.