The Porsche that Mazzoli drives, featured almost halfway through the film, has a AJ 456 MG plate, but this "format" was only introduced in Italy at the end of 1993 so would not be present in 1992 or so when those scenes happen. Correctly, Mazzoli's father's auto has a plate in the old format MI XX XXXX.
When Marco goes to his friend's radio show in the mid-'80s, a Fiat Punto (2nd generation) is shown: this model was actually marketed in 1999.