I've had just one bad experience with a car service.....when we arrived at MCO, no driver waiting for us at baggage claim. We got our bags (15 mins later), dh went looking for our driver. He was found, outside, smoking! Okay....not so great. He then walked us to the car, while we lugged the bags. Same thing happened on our return to MCO....the driver was nowhere to be found. I called the office, they said he had left long ago. Well, we finally say him, way down the driveway, smoking...again. His tip was greatly reduced on the return trip.
I can't remember if it was this same trip but we did have one driver who refused to make a grocery stop. It was Thanksgiving Day, about 11am. I had asked, repeatedly, when booking, if we would be able to make a stop since it was Thanksgiving. Not an issue...the stores are open until noon, and convenience stores are open all day. But, the driver refused, saying that no stores would be open. I asked for a convenience store stop then, nope, none open. I was really angry...told him what the office had told me. He told me that they had given me incorrect info! Again, tip was less than it would have been....and the company was contacted!!
Other than those two times, I've had very good service...even when we were rear-ended at a toll booth!! I don't usually use a rental car, but do use Garden Grocer for groceries.