I have now been in panama for three winters and each year the car rental gets worse. The fees, then the insurance and the quality are always a mystery.
This year, I rented online before coming down and ended up with a 6 year old 90,000 km car with bald tires and no shocks. I returned it after 1 day, ended up in an argument with the clerk who took my papers, refused to give them back and then refused my refund. 1 day for 1167.00 three months later even my lawyer is getting nowhere.
If Panama wants tourists, then get the car rental companies under controll, it costs more for a rental car than for a house for a month.