Bought a Car in Florida

I went to a buy here pay here dealer and bought a 1993 Honda Del Sol. I put $800.00 down and have $5000.00 left to pay on the car. There were some cosmetic issues and an "O" ring that needs to be replaced. The dealer filled out an "I Owe You" paper that states that they would fix the things that needed to be fixed with in the 1st 30 days and not to exceed $50.00. The paper also states that it is only good for 30 days from the date it was filled out. I have now made 3 payments on the car and they have not fixed these isssues. I also had them fill out another "I Owe You" paper as the first one had expired. The 2nd one expires 3/20/08. My question is what is my legal recourse to get them to fix what they had promised or give the car back and get my money back? Thanks for your help