Our rental car with Crystal Auto was exactly as expected. When we departed our flight at the Belize City airport, we walked across the street to the Crystal Auto office there. Everything was ready for us and our vehicle was clean, ran well and handled the jungle roads of San Ignacio well (we rented a 4 Wheel Drive Jeep Patriot).

The two reasons I marked it down from a 5 were:
1) I was advised by my hotel I would receive a 10% discount due to booking a hotel stay with one of their preferred hotels. I booked online and received a confirmation for a certain rate (the internet rate), then emailed them about the 10% hotel discount as I had been told to do. When they added the 10% discount I got a new confirmation and the discount was based off a different (higher) base rate. When I brought this up to them, they told me it was because I was getting a hotel discount so I was not eligible for the internet rate, which did not make sense to me since I was booking through the internet. The point of the internet rate is presumably to reflect the convenience on their part of not having to handle the reservation over the phone with me as I did it all myself online, so I should retain the internet rate. I understand some companies don't allow stacking discounts but a) that was not specified anywhere and b) the internet option was the rate for booking through a certain method, not a "discount".
And 2) When I gave them my credit card in the office to pay for the rental, she handed me back the receipt for the rental charge and another receipt for $750.00 which was apparently the security deposit. I was not told about this ahead of time (or even before charging my card with it), and it takes 1 week for the hold to be released. In my opinion that's a very hefty security deposit (the most I've ever paid in the US is $300), and I absolutely should've been made aware of that when we first made the reservation a month prior to traveling.

The return process was simple and they even give you a free ride to the water taxi if that's where you're headed next (but you do then have to return the car to a different location that is closer to the water taxi).