Hey Opie, I realize you made your post quite awhile back, but I thought I'd reply anyhow. I've been over the border at Del Rio, TX into Acuna many times, and there is only one "checkpoint" by the mexican police when you are coming back. It's basically just driving through and telling them you are US citizens. They don't care much about anything else. Now the US customs is a different story, depending on if you are driving back or walking back. Your co-worker's story sounds like a bunch of hooooooooey to me.