At San Diego airport (SAN), Dollar and Thrifty are now combined into one location. The old, pretty decent Thrifty location is closed, even though no one had taken down the sign that says "Thrifty Car Return".
The new location is dangerous. Returning the car involves a right turn from a busy street into a very small return area that can be partially blocked by other cars. The rental office is also very tight and inefficient. I wouldn't recommend the place.