If you're still in racing driver mode and roaming the streets with the speed limiter turned off, it's possible to hit the golden diamond goal marker incredibly quickly. The downside to your efficient yet fast transport is that you might miss some of Paulie's dialogues. As Tommy heads to the highlighted destination, Paulie will start talking about wanting to be taken to the ladies - “those sweet patooties,” as he so eloquently puts it. You could write off the character's intoxicated ramblings, but this is meant to steer the player toward a secret objective.
At no time did the objective marker deviate from Paulie's home. Tommy has to listen to the poor directions left by his passenger. Or you can read this guide for clearer instructions as you are doing this right now. Instead of heading for the house down the street from the Salieri bar, continue south through Little Italy and into the construction district. From there, change your direction east and over the West Harbor Bridge. Paulie will begin to show her enthusiasm for your new class. It is your indication that you are heading in the right direction.
On the central island side of the bridge, take the first right and drive south to the quays of Saint-Pierre. Turn left into the street just off the 'St. Text of Peter's Docks on the map. Finally, take the first available left turn that follows. The Blue Tropics neon blue sign can be seen at the end of the street. Stop until you reach the parking space in front of the building.
Chapter 5: Fair Play will end like it does when you bring Paulie straight home, except you now have a secret and shiny Mafia: Definitive Edition achievement / trophy to show off for the detour.
