BootsnAll Travel Community

In Dec.2000, my husband,kids (teenagers)and another family are flying into Cancun. The plan is to rent cars and drive down the coast of the Yucatan, hit some remote spots, camp some and then go into Belize. We will then try and park the cars in Belize and bus it into Guatemala to Tikal and spend a few days in that region.
Does anyone have any experience renting cars in Mexico and driving down into Belize or traveling by bus in either Belize or Guatemala? We are experiencing some difficulty from rental agencies about taking cars into Belize and have decided not to even bother with Guatemala, except to travel by bus. Any suggestions or information would be great to make this a memorable trip and hopefully not too much hassle! Also, if anyone has some favorite places they enjoyed staying please post these. Thanks!