I found a great article on eXaminer.com with all the information you could possibly need for traveling to Mexico.
Here’s the main points:
- REGISTER with the nearest U.S. Embassy: Register in person or online. The U.S. embassy will provide you with travel and security information for the area. More importantly, it allows U.S. citizens to be assisted in the event of an emergency.
- KNOW the ENTRY and EXIT REQUIREMENTS: all U.S. citizens traveling by air must present a valid U.S. Passport to re-enter the U.S. For Mexico entry/exit requirements telephone the Embassy of Mexico at (202) 736-1600.
- MINORS: Any non-Mexican citizen under the age of 18 traveling without a parent or guardian must carry notarized written permission from the parent or guardian to leave Mexico.
- VEHICLE PERMITS: Those who drive beyond the border zone (the area beyond 20 kilometers from the U.S. border) must obtain vehicle permits.
- CAR INSURANCE: If you are driving your car to Mexico you must have Mexico domiciled insurance. Your U.S. insurance will not suffice your trip into Mexico. For top of the line Mexico car insurance and service visit www.Mexpro.com.