Very interesting article by Anne Cearly in the Union-Tribune on Sunday, June 25, 2006 entitled "Vehicles armored all over: Insecurities, rash of kidnappings turn Tijuana business into a growth industry."

I liked the last two paragraphs:

Guerrero considers his workers artisans. So much
of what makes a car so secure, he said, is the touch of the delicate
human hand.

“Armoring a car requires craftsmanship,” he
said. “This is not a job in which a machine puts everything in place.
It’s a very artistic and laborious process.”