rentalcars.com a subsidiary of priceline.com rented a car that didn't exist Internet
I used rentalcars.com to rent a car in Cabos, Mexico. The rental company is Europcar. On the website and rentalcars.com's receipt it said that 3rd Party Liability was included with the rental. When I got to Europcar in Mexico they said that 3rd Party Liability was not included and they wanted to charge me an extra $30/day for 3rd Party and Collision. Collision is already covered by my Visa. They wouldn't let me rent the car without paying the extra $30/day.
I tried to get in touch with rentalcars.com that day. After some digging, I found a customer service phone number in England. I called it but there was no answer - not even a voice mail - it just rang and rang. Having no other choice, I left and went back to the airport and rented the same class car from Sixt for less than $30/day *including* 3rd party and collision insurance.
I emailed rentalcars.com immediately and got an automated replay that they would respond within 28 days. 28 days?!? 17 days later, I received an email from them saying that I cancelled my rental and the cancellation fee was the full amount I had paid rentalcars.com. Next stop for me is to dispute the charge with Visa.
So, don't use rentalcars.com unless you want to rent two cars on your trip - one from rentalcars.com and one from whoever you end up using in country.