No guarantees that I know of.
But sane attempts cost little and might work.
Take incremental phone images of the trailer loading process. Like ten in all. It may work.
Say "buenas" and shake hands. A Mexican who does not reciprocate is considered to be unacceptably crude by Mexican standards.
I would take the Something To Declare Lane then park in secondary close to where the aduaneros are working -- and not crawl along like a caught guilty party. I would open all the doors, then stand by the trailer wearing a business grade smile.
Simply displaying enthusiasm for where you are moving to can leverage a more favorable disposition. One time, entering at a remote POE the aduanero asked if I had ever been to Mexico City. I had a cargo trailer stuffed to the gills.
"Oh yes!" I replied "But I made a big mistake -- I should have allowed triple the time visiting". He gave me a wide grin and waved me through.
This last trip I declared merchandise to be sent to my family. I asked politely for a discount because I was "a poor pensionado" He valued two hundred dollars worth of merchandise then wrote $100 MN on the receipt. I sent it off ESTAFETA with the Tarifa de SAT pasted on the outside. It arrived 5 days later.
Good luck to you.
