Most of the negatives stories are spread by the Peoples’s press and by the USA gouvernement.
It is true that there is a drug cartels war in Mexico. And most of it occur on the border towns like Ciudad Juarez. I never stay long in the North. I always cross at Laredo and never had any problem.

I never, said NEVER had a bad experience in Mexico after 30 years of traveling in this nice country with so nice and welcoming peaples.

I thing that the keys are:

1- Speak a bit of Spanish
2- Smile
3- Be low profile
4- At the border, do your papers works early morning and drive South fast.
5- Try to skip the big touristics cities like Acapulco, PV, Cancun, Mexico City, etc…The bigsTourists Cities attracts the punks and thiefs.
6- Never show that you have more money than them…
and again, try to speak the language…

Good luck…and goMexico

Merci

Frank