For example, if you enter Costa Rica on the 1st of October, but your vehicle enters on the 1st of November, you will only have two months to drive the vehicle, not three. This is very important to keep in mind. At the end of three months, you have the right to extend the right to drive the vehicle for an additional three months. If you wait until the three month period is up, theoretically you are required by law to pay the taxes on the vehicle. We highly recommend that you do not drive the vehicle if the permit has expired.
Any vehicle being driven after the permit has expired is by law, an abandoned vehicle.
The police have the legal right to confiscate the vehicle and not give it back. Most likely, they will compound the vehicle until the taxes are paid. Either way, it will not be fun. If you are pulled over and cannot produce the documents, they will detain you and most likely compound the vehicle. Do not, under any circumstances, allow a local Costa Rican to drive your vehicle.