Belize: Drive through Mexico experience:
I recall reading every drop of advice that could be garnered in regards to what to expect and how to do a drive through Mexico from the US border to Belize.
It was awful. Plain awful. And not without several particularly uncomfortable incidents with the uniformed bandits posing as police.
Guys, do not bring your wives or girlfriends on the trip and opt instead for a buddy, if you must drive. I promise your spidey senses will be at an uncomfortable '11' the entire time if you're having to worry every time she (or your kids) have to leave your sight.
Will anything bad happen ? Likely not. But the chances of such are far greater than one's daily routine in the US and it'll be palpable almost immediately after passing the border.