I've never been overseas, so I don't know what's available for rentals. But I did book a car in Miami for this December and Sixt has a facility there and the website offered some great prices on nice cars. I was "this" close to booking until I did a little research and found nothing but complaints from customers about Sixt's poor business practices, horrible customer service, unexplained charges, claims of damage, etc. from people in pretty much every country where Sixt is available.