Has anyone done it? We're going in the summer and been looking at excursions, but they seem very expensive and we're not huge fans of organised coach tours. Thinking of just hiring a car for a day or two to go and see the ruins at coba and tulum and maybe a few other places once I've done more research. The driving itself doesn't bother me, I've driven abroad a fair bit in the past, but more concerned about whether it's safe (we'll have our DSs 7 and 12 with us) and any tips?