Now that I've been to Belize and gone through the car rental process in person I wanted to report on my experience. After considerable earlier research and inquiry on this forum and elsewhere I did end up using AQ Belize Car Rentals. The main attraction was that they provide a $1 million liability insurance cover per accident that comes along with the car rental base rate. Their closest competitor offers only $20,000 cover. This was the critical factor in our choice to use AQ. We were told when we actually arrived and were chatting with the staff that this is one of the ways they try to differentiate themselves from the "other guys" since this is a very competitive market. We were very pleased with our rental, had no problems with the car whatsoever although it is certainly true that their cars are not shiny new and do show their age a bit. This is actually preferable for us, as long as the dents etc are well documented at pick-up of the rental. AQ was very conscientious in this regard. We would certainly rent from them again.