We use to go to Mexico every Winter (4 years). I just became too much of a hassel. Every border crossing, constant check points, can't tell good cops from bad cops ( even the good cops wanted a few bucks for directions or what ever). We have driven every state in Mexico and there is pretty country strown with trash. Most parks had poor electric water and sewer with garbage deposed of on site, yet charged stateside rates.
I thing the biggest thing that stopped our travel to Mexico is not being sure of which agency would honestly help us should something happen. Let's say we did find an honest person to help us; how are we to know if the persons he has to deal with are not corrupt. This is also the reason several people we know have quit RVing in Mexico.