Looking at a trip for next April, towards the end of the month.
It would be the last day before flying out of PMO. I can either return the car before that last day or return at the airport on the morning of my departure.
I've seen other threads suggesting Castellamare del Golfo, only 20 minutes from the airport. I've stayed there on a previous trip, really nothing much to see there.
What if I wanted to spend the afternoon driving to Monreale or the top of Monte Pellegrino and then driving in the morning to the airport, with a need to refill the car before returning it?
Is there some location near those attractions but without getting caught up in the traffic, especially the morning of my flight, which would depart around 11:30 AM? I know Vagabonda has repeatedly advised avoiding driving in or near Palermo itself.