Hard to say without reading all your sales papers and going through the whole story with you. Rebecca Covey and Bob Murphy are in the Ft Lauderdale area and they know Florida car sales law extremely well. Angelo Marino is there also and Florida has lots of great Consumer Protection Lawyers. You can find their contact info at www.USLemonLawyers.com. Call one and go over it so you can be sure what your state law says your rights are.
This answer is for general purposes only and does not establish an attorney-client relationship. The law in your state may differ and your best answer will always come from a local attorney that you meet with privately. For a Free Online 50 State National List of Consumer Law Lawyers, click on this link (http://tinyurl.com/79ku5jx) and find one near you
Mr. Burdge is correct, a through review of your purchase paperwork is required and Mr. Murphy and Ms. Covey are well versed in this area of the law. The dealer's promise to repair certain items is considered an express warranty and need not be in writing; the dealer should be required to perform under this warraty. Whether you can require the dealer to also warrant an overheating condition that arose later will depend on additional facts.
Disclaimer: This response is based solely upon the limited information provided in your question; additional facts may be necessary and may lead to a different response. The attorney responding to this question is licensed only in Florida and this response is intended for informational purpose only and not intended as legal advice in your particular state. Additionally, the response is not intended to create an attorney client relationship.
Mr. Bolliger is modest as he too is an excellent consumer protection atty. Find him or Dana Manner or any of the other fine consumer protection attorneys noted here: