*Shrug* Old lorries, armour plate bought from a scrapyard, and armoured glass (That's a bit harder to get.). Not exactly "High Tech". You just need a really good welder, and you'd have a WWI/Early WWII-Era Armoured Car. Certainly is stepping things up from Technicals, however.
And if there's anything the NarcoTerrorist Gangs have is money. More than they could ever launder effectively. Which makes jobs like this so much easier.