I am in Montevideo for a few days and have discovered that the GST (iVA in local parlance) is automatically refunded if you pay car hire or restaurant meals with a non-Uruguayan debit or credit card. It is targeted at Argentinian visitors but we all get to benefit. The refund works out to be about 18% on restaurant meals and around 9% on car hire.
The link says benefits expired in April but they were extended.
https://youtu.be/4paLVu0gNcQ