With the implementation of the Value Added Tax (VAT) on July 1, 2019, renting a car in Costa Rica will be more expensive: 13% more expensive. This in addition to the already ridiculous high car rental prices in the country.
Currently (on rentals up to and including June 30, 2019) only vehicles rented from the airports have the 13% sales tax applied.
For example, a vehicle rented at a hotel or car rental location say in downtown San Jose or at the beach (other than the airports), do not have the 13% sales tax.
However, ALL vehicles rented as of July 1, 2019, and on will be taxed.