For anyone looking to rent from a reputable firm there are many to choose from. Our favorites are ISIS, Avant, America, and GoCarrito. Just compare prices at that time, they all include all the insurance you need in the price except tire and glass, and road service. They also all deliver and pick up at CUN or at your hotel. Avant is located in Cancun area, while the others are based in Playa (and Cozumel for ISIS). We also get the added insurance for peace of mind in the event of damage to others even though we have some CDW coverage with our cc. Definitely get liability ins...
We're just getting title to our new place and look forward to living there too...