Rockstar set up a special GTA 6 team in Miami to meet with "ex-criminals, law enforcement, club promoters, gun dealers and anyone notorious or influential"
Rockstar went to some great lengths for its Grand Theft Auto 6 research, it seems, as the studio has said it sent multiple teams of developers to Miami as well as embedding a team there longer-term for research. Read more
We haven't written up this one. Eurogamer has the full story — the link below goes straight to it.