Just a follow up. The Budget franchisee (cheapest major - only Hertz and Thrifty still there otherwise - after discount codes) has very old and defective cars. First one they tried to palm off on us was a Suzuki Jimny which was not pristine by any stretch. Quite a few dings, worn paint, and shortly after leaving the airport (USD just to take a vehicle out of the parking lot), found that the vehicle wouldn't stay in 4th gear (even if you held it there). Took it back and they said they're waiting for parts. Got an old Hyundai SUV which was worse for wear, had a worn-out front end, and 4WD switch knob that was broken and they tried to epoxy it back (better to give a small pair of vise grips), and both vehicles had over 170k Km on them.
There are many local rentals cos and they may have better representation countrywide. The majors appear to only have active offices at the airport and Belize City.
BIQ for the next little while