You have to: Complete all "career"-missions.
Complete all side missions (Such as those with Love Fist, Phil Cassidy and Mitch Baker)
Complete all asset missions, that are unlocked when you buy properties.
Complete all Sunshine Autos Asset Missions (Such as the street race)
Complete all other missions and extras: Payphone Assassinations Stadium Missions RC Toyz rampages and drive challenges Off-road races Chopper Checkpoint Races Knock off stores Buy all property Set a highscore at the rifle range
Complete all Vehicle missions:
Vigilante level 12 Firefighter level 12 Paramedic level 12 Pizza boy level 10 Taxi missions (100)
Complete all rampages (35)
Complete all unique jumps (36)
And last but certainly not least,
Find all Hidden Packages (100)
Good luck! (Feel free to contribute with locations, or other relevant info) P.S the text turned weird on the Vehicle missions, can somebody please fix that?