They said when someone uses the autoexpress after declining to pay up front, there is a $50 charge. Upon returning the car, I explained what I had done, since I had no other choice to pay at the toll booth. I used the sticker several other times during the three days we needed it and figured at $.75 for each toll, I had racked up a whopping $11.25 worth of use. When I approached the first toll, I pulled over to the 'pay as you go' line and the attendant said, 'You can't pay cash, you have a autoexpess sticker and it has already been charged! Besides, there is more than $1,000 dollars on that toll pass' (No wonder if they get $10 a day from suckers). But out of our ten days in Puerto Rico we were only going to need the toll pass for three Days! It was $100 or nothing! No other offer. They offered to provide autoexpress for $10 per day. I was informed that you couldn't always pay at some tolls because they only allow autoexpress tags. I said we would be going to the end of the Island and would just pay at each toll. The price was acceptable until I arrived and they asked about using the car on the highway where there were toll roads. They picked us up at the airport and returned us as promised. I reserved the car ahead of time on-line.