Just a warning to those who rent a car from Hertz in the Carrasco airport. When we picked up the rental car, I tried to use my Amex card. He kept swiping my card saying it won't go through and I ended up using my Visa. Thankfully I keep all receipts! Turns out he was putting all those charges through my Amex card. On my statement I have an $850 charge. My Visa was also charged $240, which was the correct total. I had to dispute the $850 charge with Amex.
Keep your receipts and beware of Hertz in this airport!