My wife and I own an old 1994 Mercury Villager, and in December 2008 the distributor belt broke. We had a wedding to attend on December 28th 150-ish miles away in Talequah. The van wouldn't be repaired in time, so we decided to rent a car.
We went with Enterprise, and reserved a 4-door small saloon, since we would need a back seat for our (then) 9-month old sons car seat. My wife was concerned they wouldn't get our reservation (since we did it online) so she called in to confirm. They confirmed yes we have your reservation, the car will be waiting. Ever the worrier, my wife called twice again later in the week, and finally the day before. Same answer, yes we have your reservation, a car will be waiting.
Well, we get there, and the manager (a sour faced gentleman) informed us they had the perfect little 2-seat pickup. I explained thats not what we reserved, because we needed three seats. One for me, one for my wife and one for my son. A 2 seater wasn't going to work. He informed me thats all they had left (this was 9AM, opening time, and they had ONE car?). I asked him why they had repeatedly told us they had a car for us. He said they could only guarantee an "equivalent vehicle". I explained that a 2 seat pickup was in no way equivalent to a 4 seat saloon, apart from both possessing wheels and an engine. He became agitated and repeated "Well thats all we have". I stated that this was the most useless company I had ever had the displeasure to deal with and left.
Fortunately, my mother in law, upon hearing the tale, decided to take a day off and also attend the wedding, and so we did get to go and didn't disappoint the bride (a close friend of my wife and mother-in-laws). However, this was NO thanks to Enterprise-Rent-A-Moron. Had we been completely reliant on them, we would have been left high and dry. Fortunately no money had exchanged hands at that point, had it done so the manager would have given me a refund or been picking his teeth out of the upholstery of said pickup truck. Lest to say, we were not happy.
The moral here? If you have somewhere to be and a particular requirement for a vehicle, don't use Enterprise! You'll ask for a Mini-van for you and your 6 kids and they will give you a scooter and call it an "equivalent"