We're flying to Albuquerque in a few weeks, and renting a car to drive up to Colorado. All we can do is hope that the car we reserved will be waiting for us at the airport. Tales of rental shortages are widespread and many would-be renters have been dismayed to find out there's no car available.
Christopher Elliott's column in USA Today covers a lot of ground (no pun intended) and is worth reading. Unfortunately, we don't see any tips that would help us in the event our rental fell though.
We'll certainly check out some of the apps he recommends.