From my experience, you probably won't get a full refund. For instance, I had a Malibu with 4,000 miles throw a CEL and reduced engine power light and went into limp mode on a 2 lane 70 mph bridge, and all Hertz was concerned with when I went to swap was that the gas tank wasn't at full. They make make a small adjustment though. But next time take the car in if you are truly that dissatisfied and they're generally pretty good about swapping, especially if you have a CEL on. Plus, Miami usually has an abundance of convertibles. Definitely agree social media is probably the way to go!