Yes.
Yes, you need a passport to fly out of Tijuana.
Yes, you need a passport to fly from Tijuana to Guadalajara.
You don't need a passport if you are coming back from Tijuana, I asked the immigration people and they said it's fine with the ID and Birth Certificate. Actually if you go walking there are 2 lines one for passport and the other one is for people that don't carry passport.
U.S. citizens do not need a passport to enter Mexico by land or sea. The Mexican officials at the border do not ask for any identification from you. On your return home, the U.S. officials would like you to carry a current passport but they can't obligate you to do so. Every day hundreds of people cross from Tijuana to San Diego with only a driver's license. See related links section.
You don't say from where you are driving. I assume you mean to cross the border, so you would need a passport. You might also need a visa - you should ask your local consulate.
A passport & a lot of protection ! People are getting mugged down there left & right. Stay out of Tijuana until they get better protection for tourists !
You need an American ID, birth certificate or US passport. Note you don't need anything to cross into Mexico; however you will need any one of these documents to return to the United States.
Yes, the three of you will need a passport.
No, you cannot cross the border with an expired passport from 2016. You need a valid passport to travel internationally.
A passport is needed to cross any international border.
No!
You do not necessarily need a passport to cross the USA border from Canada if you have a driver's license.