Good afternoon. I am Loren, a Florida licensed attorney, and I look forward to assisting you. I am sorry to hear of your dilemma. I realize how frustrating this is for you and I hope to provide you information which is accurate and useful, even though it may not be the news you were hoping to get.
Since you have a written warranty, that would supersede any oral promises for maintnenace or condition. So, if the warranty has any provision for the dealer or manufacturer buying the car back from you then you can exercise that provision.
Otherwise, once you take the car off the lot and pay the purchase price, the car is yours, along with any maintenance issues not warranted in writing.
You can file suit in small claims court if they breach the warranty (though check the terms of the warranty for mandatory arbitration), but the warranty is the document which would control your legal remedies if the car has defects.
You can also file a consumer complaint with the Florida Attorney General. They will investigate and take action if warranted.