Polvadera literally translates to "dust cloud" or "cloud of dust". It's a vivid and somewhat less common word that paints a clear picture.
In the context of this song, it's used to describe the visible aftermath of fast movement or activity, as in "Sólo ven la polvadera" (They only see the dust cloud). It suggests a sense of speed, action, and perhaps leaving others behind, which fits the song's theme of living life on one's own terms.
Aldo Trujillo's "Legends Never Die" is all about living life to the fullest, on your own terms. He talks about enjoying the good times with "hierba bien buenas en el camarón" [good weed in the shrimp] and rolling up to make "buenos momentos" [good moments]. It's clear he's found his stride, saying "yo tengo mi estilo una mochila para cargar el efectivo" [I have my style, a backpack to carry the cash] and he's not afraid to spend it. He even laughs at those who doubt him, saying "me río de ellos" [I laugh at them].
He's living proof that you can make your own way, declaring "disfruto la vida yo hago mi mundo y las cosas a mi medida" [I enjoy life, I make my world and things to my measure]. He remembers a time when he didn't believe he'd be doing something important, but now he's enjoying a "trago duro a las rocas con la ley bol preparado" [hard drink on the rocks with the label prepared]. He's enjoying his success, with "mis carros del año" [my cars of the year] in the neighborhood, and he's not going anywhere, stating "yo me quedo no me muevo en leyes de verdad y sigo viviendo me sigo riendo" [I stay, I don't move in real laws and I keep living, I keep laughing].