Same as Roslyn. We crossed at Sonoyta yesterday. I walked over, handed the agent our fmm's, asked him to stamp our passports 'salida' which he did. Makes me think we are squeeky clean.
we then proceeded to the border. The young, nice lady asked if we had anything to declare. I said," we do have some things we aren't sure about, some frozen carne asada, some all beef hot dogs, and a large lava rock." She said she would have to get agri about the rock, but everything else was ok.
The agri lady came out & said, " Why would you want a rock?" I said, " because I want it in my front yard at home." She said I could keep it.
That is why we cross at Sonoyta, friendly and reasonable people.