Once in awhile, the mexican agricultural folks check food stuff, (meats, alcohol, etc) at the border. Had it happen to us twice on the way southbound through Lukeville. Not a big issue. We've only had it happen twice in 15 years of traveling to Puerto Penasco so thats not too bad. You don't need to bring much food stuff with you southbound as there is a Sams Club and a Walmart owned store there for groceries. You can check online for foodstuff allowed and not allowed at border crossing. We head there every Feb. As some stated. Don't speed, especially through the border town of Sonoita.