I'm happy to do so. The first incident was with Avis in El Salvador. We wrote "signed blank" on the form. The counter agent said "You're not supposed to do that" but let us take the car.

The second incident was with Payless in San Juan, Costa Rica. I've detailed our experience above. On our return, we wanted to use some colones on our bill. They would not allow us to do so. They said the entire bill had to be charged to the credit card. Their reason: we had only paid for basic insurance and declined additional. Therefore they claimed that the entire bill had to go on the card which would have provided additional insurance if needed.