To get unlimited ammunition for the following weapons, you must collect the indicated number of weapon icons scattered around the city.
60: Unlimited grenades
Having A Bullet Proof Car
70: Unlimited hand gun ammunition
80: Unlimited sawn-off shotgun ammunition
90: Unlimited grenade launcher ammunition
100: Unlimited rocket launcher ammunition
Find a car driving the street, jump on the car and let in drive till it reaches a good speed (you can shoot in the air to make the car drive faster), after you are at high speed shoot a cop to make your adrenaline meter visable, then do a slow motion shoot dodge, after that you will notice the driver in the car will be out of the car and the car will drive without a driver, you can enter it and it will be bullet proof!
Indestructible Taxi Car
If you steal an occupied cab (the ones that offer to take you from city to city, no matter the car model) by shooting the driver and taking it, the cab will be indestructible while you are in the driver's seat. Even if the cab takes damage while you are out of it, it will still remain indestructible once you jump back in it, even it is has cosmetic blemishes or broken windows. However, if you wander too far away from the car, a taxi driver may re-appear in the driver's seat, but the cab will be where you left it. You will have to kill the driver again if this happens.
Complete all game missions to replay any mission of your choice.
Dual pistols upgrade
Collect ten weapon icons.
Dual rifles upgrade
Collect twenty gun icons.
Collect ten health icons to upgrade your total health. This can be repeated.
Collect ten stamina icons to upgrade your total stamina. This can be repeated.
Play as Ram
Complete The Good Son mission.
Play as Ram's brother
Complete The Father mission.
Bike in the Bull Ring
Complete the Kill The Bull mission.
DEA and military vans appear
Complete the mission Make Elvez Sing mission to make locked DEA and military vans appear. After the game is completed some of them will become unlocked.
Racing cars appear
Complete the Steal The Wheels mission.