My only nightmare car rental experience was through hotwire for Budget at LAX. We arrived at Budget to see the line of people snaking outside and around the building. It took us 3 HOURS to get a car. When I go to the front of the line, after 2.5 hours of waiting, I was told they "didn't have" my car. I was at the point of tears. I told them I needed a car NOW. 30 minutes later they offer me a full sized van. I had signed up for a compact car, but I wanted to get out of there, so I took the van. Most miserable experience of my life.
Budget was unapologetic. It was a Saturday in July and they just insisted they were "busy" for the summer season. There were people in line frantic because they were going to a wedding. People were calling cabs to go to other car places to try and get cars. But because mine was a hotwire, as were most of us in line, we had prepaid and were locked in.
NEVER AGAIN! I would never rent from Budget out of LAX for as long as I live! LOL! For that reason, I probably wouldn't do a hotwire out of LAX if it was for a Saturday because I might be stuck with Budget. However, I would for another airport.
Car rental prices change faster than a teenager changes clothes. Keep checking and checking and looking for deals if you decide not to go with Hotwire.