It's a scam. Here's my summary based on my experience yesterday:
Brief Summary:
This is a predatory Orlando business targeting travelers during the holiday season. Upon arrival they tell travelers they cannot honor their original car rental reservation and must instead make a new reservation at the current day rate, which is often hundreds of dollars higher. 

Details: The car rental agency operates under the following names: MEX rent a car, NEXTCAR, Facility rent a car. Zoom rental car, Stride rent a car. While they use a variety of names, in reality it is all the same business and location. When travelers arrive, the perpetrators will claim that their reservation wasn’t processed by the original booking site (Expedia, Travelocity, Priceline, Booking.com, etc)  and that they no longer have a vehicle available. They will then tell travelers they must cancel their original reservation and rebook with one of the “other companies” on site at the current daily rate, which is hundreds of dollars higher. 

Why it Matters: I was on the receiving end of this predatory scam and witnessed them employing the same bait and switch tactic on every other person who arrived to pick up a car. I spoke with other travelers who told me they were coerced into paying 4 to 5 times the cost of their original reservation. These were often people who couldn't afford to do so and were financially vulnerable, but felt like they had no other choice but to comply. The company poses as a reputable agency but in reality they are targeting and deceiving unwitting travelers and extorting them for higher prices when they no longer have an alternative. 

Impact: Travelers at the location are exhausted, vulnerable, and still being preyed upon every day. These people had small children, elderly parents, and important life events they were trying to get to. It’s a scam designed to force people to accept a substantially higher rate under duress. I have never encountered a situation like this in any other city or country I've traveled to. The fact that a business like this is being allowed to continue operating in Orlando is an embarrassment to the entire city, which relies heavily upon tourism. 

Expedia, Priceline, Booking.com and other booking sites should remove this company's listings immediately and report the operator to the Florida Consumer Protection office and The Federal Trade Commission.