Mistakes/failures can occur but it is how a company handles it is the important thing. I think you could have been treated better by the dealership and kept updated on the progress. With regards to the Enterprise car out for another Ampera it could well just be the situation that it is as a courtesy car while the owner's car is in for servicing. I had this with my current Corsa, it was Enterprise that supplied the courtesy car and again it could have been cleaner but although they were pleasant and polite I got the impression the supply of courtesy cars was not their top priority.
