Car rentals in Belize are expensive, and generally you will only find small four wheel drive vehicles and jeeps for rent. The reason is simple - the roads in Belize are horrible, with the exception of three main highways (the Northern Highway, the Western Highway, and most of the Hummingbird Highway). This also explains why the car rentals are running US$80-US$100 per day.

Be careful when renting cars in Belize.  Deal only with reputable rental agencies, since there are many Belizians who will rent you their personal cars!  We rented a Suzuki Vitara from Budget Belize, and found the people at this agency very competent and professional.  I would highly recommend renting a hardtop vehicle versus a jeep-style vehicle.  You will need protection from the relentless sun, and air conditioning is a must.  The dust on the roads can literally choke you, and the torrential rains and flying stones can also be mighty unpleasant in an open air vehicle!   Seatbelts are also essential, since the roads in Belize are "rough".

Gasoline prices in Belize are about the same as we find in Canada, but Americans might find the prices slightly higher than they would find at home. Belize doesn't have outrageous gas prices like some other Caribbean countries.

I would recommend renting a car if you want to see a number of sights, and are good at planning and navigating on back roads. Otherwise I would suggest that you fly to destinations and hire tour operators or taxi cabs for tours of the local sites. Domestic airfares are inexpensive ( approximately US$50 one way), however if you are not comfortable flying in small planes and landing on short, dirt strips, then perhaps land transportation is the best option afterall.

Maps

ITMB - Vancouver, BC, Canada - A map dealer specializing in international travel maps.  Get their inexpensive map of Belize: