You are in for a wonderful surprise as the Mexican bus system is one you would expect for a "frst world country,"unlike the third class system our "first class" US has! Visit the bus depot 24 hrs. in adv. of travel, check out the buses in the lot and the reservation desk for the busses you think you like and can get a seat for the time you want to leave. We went Primera Plus and it was clean and had movies like an airplane. You get a snack and a soda right upon boarding. Know the first class busses go from major city to major city and do not stop for you to eat a meal. The super busses go for the overnite traveler-seats recline a lot and you can save the price of a hotel. I would feel very safe traveling first or second class (which is quite acceptable) Two drivers are required by law. I doubt you would be hassled at all but learn to say- No te metes comigo! Dejeme en paz! (dont mess with me and leave me in peace) and say it loudly.