Enter The Codes at the Cheats Menu

You can find these under the "Exotics" menu, and "Investments" option. The purpose of the investments is to provide upgrades to the game or to your player. You will need at least $1.5 million ($40 million for Montana Legal and $20 million for Montana Sports) to purchase most of these investments. The investments will help you level up faster.

Save the game before attempting this. Go into the ocean from anywhere and start swimming, preferably away from land. After a while a giant shark will appear and eat Tony.

The only way to get a car off the road is to get in front of it and push T. Keep pressing it. If the person gets out, you get balls.

Enable the BUMMER code. Then, go after the gangs with it. The gun will have unlimited ammunition and enough armor to take them all out. If you run low on your vehicle's health, enable the TBURGLR code. However, you must move your Hummer once in awhile or they will pull you out. This also is very useful when taking over the storehouses because of all the armor it has.

Some characters like the assassin and enforcer have stronger weapons. For example, play as the enforcer. Call for one of Tony's cars. once it arrives, go to the weapons trunk. Place the grenade launcher in the trunk, tehn switch back to Tony. When you go to the weapons trunk, the grenade launcher will still be there. You can do the same thing with the assassin to get the PSG-1.