go to Mexico for vacation

Flight to mexico or cruise to Mexico bus/car with train
Flight to mexico
From Australia: The cheapest way to fly to Mexico from Australia is via Hawaii (i.e. with Jetstar) and then onward to LA Hawaiian Airlines. Direct flights (or via New Zealand) are also available but cost two to four times as much.
with car go to mexico
American automobile insurance is not accepted in Mexico, however it is easy to obtain short-term or long-term tourist policies that include the mandatory liability coverage, theft and accident coverage for your vehicle, and often, legal assistance coverage.
with train :
There is at least one place where Mexico is accessible via rail and a short walk - south of San Diego. The San Diego Trolley can be taken from downtown San Diego (which Amtrak serves) to the California-Baja California border. (note: El Paso/Juarez is also well served by Amtrak, the station is within a stones throw of the rio grande)
with bus
The Mexican bus system is reportedly the most efficient in the world. There are many different independent companies but all use a central computerized ticketing system. Rates per mile are generally comparable to those of Greyhound in the U.S., but there are more departures and the system serves much smaller villages than its American counterpart. There are many bus companies based in Mexico with branch offices in major U.S. cities.
cruise to Mexico
Border crossing from Guatemala.
Cruise ships from United States.