Originally Posted by Tasty1

I wouldn't rent a car but use bus, taxi or taxibus. But for long trips renting a car is more fun. But if you want a real "Maya Tour" and travel to ruins, i would use ADO busses and make a roundtrip and travel back by Belize.

From the airport ADO busses to center Playa del carmen and than Taxi (when needed).
Or (private) shuttle. Both work fine.

The police might try to search you for weed, or not having passport, so you must pay them.
Keep most money in your shoes.

I would go for a nicer destination. Or maybe do Isla Mujeres and Holbox. As long it isn't Cancun