Unless you can pre-pay the Mexican auto insurance which you generally cannot. What happens is they advertise very low prices on-line (10-15/day) but when you get there you will be paying $40-60/day for the insurance. Either that or you have to put a deposit for the cost of the vehicle on your credit card. (8-10k deposit usually).

If you have not driven in Mexico I would take the tour to Chichen Itza bus tour. Tulum is much easier to get to as it is right off the main highway that runs down the coast. BM me if you need additional information. I have been to Cancun/Maya Riviera so many times I'm practically a local.