Laminadas is slang for armored or bulletproofed vehicles. The word comes from lámina, which means a thin sheet of metal.
In this genre of music, singers often boast about their powerful, modified trucks. The line "Montado en las laminadas" (Riding in the armored ones) creates a vivid image of someone cruising in a bulletproof truck, painting a picture of a dangerous and high-stakes lifestyle. It's a great example of slang that's specific to the world of 'corridos'.
This song is a corrido bélico, a type of modern Mexican ballad that tells stories from the world of drug trafficking. Luis R Conriquez and Neton Vega sing from the perspective of a high-ranking enforcer who is loyal, dangerous, and enjoys the finer things in life. He makes it very clear who he works for, shouting out "A la orden de Archivaldo" [At the command of Archivaldo], a reference to one of El Chapo Guzmán's sons. The character is impatient—"La paciencia no es lo mío" [Patience is not my thing]—and isn't afraid of violence, warning rivals "Pónganse bien vergas si ando en el sector" [Get your shit together if I'm in the sector].
The lyrics are full of specific details that build this persona. He likes fast cars, especially his Shelby, and wears a flashy watch—"un relojón / De diamantes finos" [a big watch / with fine diamonds]. He drives a bulletproof truck, a "Cheyennón" [a big Cheyenne truck], so that "los tiros pura verga nos entren" [the bullets won't fucking get in]. The whole song is a blunt statement of power and a warning to others. The title itself, "Si No Quieres No" [If You Don't Want To, Then Don't], sounds like a casual but serious threat: stay out of the way, or else.