Just my 2 cents
You know there is two side to every story....we go down 2 to 3 times a year and rent a car from one of the local business (Smart Rent a Car). We have never purchased the collision insurance because we pay with ower Canadian Master Card that has the collision coverage anywere in the world. Yes annual fees are more but worth it!
What this mean is that I have to pay up front and with a police report get a refund. I know it's going to be a pain in the butt but we are willing to take the chance. We park in parking lots never on the street. If we want to both drink then the car stays at the hotel and we take a cab end of story.
We have been caring our bank card with us at all times just for this type of situation. This way I can go to the bank machine and take out the amount I need right away.
But I leave on the Island so if I get into a snag I would not worry about it take it esay go to the police station and just figure things out. One advantage we have I do speak very good Spanish and that will serve you well.
A cruser is will always be an easy target for this. But I feel the same has them you have understand what they are asking for before you panic. In this case I have a feeling the taxist was looking for 400 pesos but since they never paid all day in pesos they just asume US dollars. Since everyone saw the same opportunity they just jump on it.
Any were you go just be carefull and don't wait to the very last minute to doing thing like filling up your gaz tank.
Lyne from the land of forst and snow