The Crystal Auto office is just across the parking lot from arrivals. And it's not a big parking lot - or a big airport.

Just a short walk across the parking lot.

It is right outside the exit of terminal. There is no need To take a bus or shuttle

As you exit the small airport, their office is right across the parking area where all rental cars are located. Easy.

The car pick up is right across the short parking lot. Very easy to get to even with luggage and children. It's 100 yards at most from terminal door.

It is close, but the path is not good and could be difficult with kids and a trolley / luggage. I did not see porters, but they may be there. Be aware of the add on's with Crystal. I thought I took out all insurance, but apparently I missed the optional window insurance and I got 2 small chips (highly likely on Belize roads) and they charged me $200 US.

Crystal rental has a location at the airport (no bus needed, it's literally right across the street, a 1 minute walk), and another one closer to Belize City. I believe you can use either one. I picked my car up at the airport, and then dropped it off at the location closer to Belize City