Papamobile refers to the custom-built vehicle used by the Pope. It's a very specific and recognizable term, making it quite unique to find in a rap song.
In the lyrics, Bresh uses it to create a vivid and somewhat humorous image: "Cammino a un metro da terra come in papamobile" (I walk a meter off the ground like in a popemobile). This line conveys a feeling of elevated status, confidence, and perhaps a touch of untouchability, contrasting with the usual themes of a rap song and making it memorable.
Bresh opens this one sounding like a man who has just won at life, and he keeps the joke going a line longer than most rappers would. "Oggi, sì, mi sento il Papa, ho la Papa Ganja in casa" ("Today, yes, I feel like the Pope, I have Papa Ganja at home") is already a stretch, and then he doubles it with "Cammino a un metro da terra come in papamobile" ("I walk one meter off the ground like in a popemobile"). New life, new house, and a woman who has stopped pretending not to care. What he notices about her is small and exact: she puts the mascara back in her Hermès bag, her makeup is half off under the white lights from the street, and she has drama with her mother while wanting to stay loyal to her father.
Then the chorus pulls the floor out. "Non sei una come le altre ma nemmeno come me" ("You are not like the others but not like me either") is the line the song turns on, and the title only shows up near the end, almost in passing: "Pensavo di trovare pure io la mia Angelina ma" ("I thought I'd find my Angelina too but"). Angelina Jolie is not a person here, she is the ideal partner Bresh keeps not quite finding, and that little "ma" ("but") is doing most of the work. The second verse is all swagger, Craxi disappearing to Hammamet, a villa in Mombasa, an Al Capone/cappone pun that is a bit much and knows it. Then it lands on "Vorrei un giorno trovarti di fianco la mattina ma" ("I would like one day to find you next to me in the morning but"). Same conjunction, same shrug.