All credit card companies say the same thing - you're covered for collision and loss-damage waiver around the world. I've filed a few claims over the years, and they do eventually come through. It's a hassle, but enough letters and calls will eventually get you the benefit. (Note that most cards exempt rare or expensive autos by market, so no coverage for Cadillacs or BMWs in the US, although they usually cover small BMWs and Mercedes in Europe. In Argentina, they would probably cover a VW Gol but not a Passat.)
The problem is with liability insurance, which covers damage or injury you cause to others. To my knowledge, this is never included as a credit card benefit. In the US, Europe, and Argentina, it's required to license the car, so it's covered by the rental company's policy. It's the liability coverage that the UY rental agents claim is not provided in their rental fees.
(Note that even in the US, the rental company almost always provides no more coverage than the legal minimum, so a bad accident that the authorities determine to be your fault could still be costly to you. Many private car insurance policies include liability coverage when you rent, so car owners may have some additional liability coverage.)
The catch-22 I mentioned in my earlier post is that the UY agents sell only insurance
packages that include the supposedly - at least according to their agents - mandatory liability coverage
as well as high-deductible collision and LTW coverage. By buying the collision-LTW, you decline your credit card's coverage, which typically includes no-deductible collision.
So, let's say you return the car with a dent acquired when the car was parked on a street, or for that matter, a dent that you didn't notice when you rented the car or didn't bother to document to the company. If the repair costs U$ 500, your credit card insurance would either pay the company directly or reimburse you in full when the company charges the repair to your credit card. But if you buy an insurance package from the rental company that includes a U$ 300 deductible for collision damage, you automatically decline your credit card's coverage, and you will have to pay that U$ 300 deductible out of pocket.
On the other hand, assuming the rental agents in UY aren't lying, if you decline the insurance package, you would have no liability coverage other than whatever your personal auto policy provides for rentals in UY. If you don't own a car or your personal auto policy doesn't cover rentals in UY, you would be personally liable for any and all damage or injury to other parties that the local authorities determine to be your fault, including potentially pain-and-suffering grants, long-term care, permanent disability, etc.
I emphasize
"that the local authorities determine to be your fault" for reasons that I hope are obvious to readers of this forum.