Unlock the P.L.A.V. faction and get a gunship with rockets, such as a Castro V Attack chopper or an Anaconda from the pirates (carries about 80 rockets). Fly to the city of Merida and shoot the billboards to earn $5,000. If you shoot enough of them, you start to unlock more shop items from the P.L.A.V. and a couple things from the U.P. mercenaries in their city. Only one rocket is required to destroy a billboard. It only takes 1 rocket from a gunship to destroy the billboards.
Start the Winching challenge on level 1, 2, or 3 and bet as much as desired. Get in the helicopter, pick up the toolbox, and hold X to fly directly up while remaining inside the drop zone. Release the toolbox when reaching at least 100 meters altitude then immediately press the Left Analog-stick in any direction while holding X until the altitude meter of the toolbox no longer decreases. The toolbox and you will stop in mid-air, allowing you to easily earn money.
When going for 100% in all tasks, be sure to complete all outpost missions before initiating the final story mission (Battle for Caracas / A.N. or China). Once the game is cleared, you cannot initiate outpost missions anymore (which unlocks a faction's shop items).
Unlock the following bonuses by performing the corresponding tasks:
BONUS - HOW TO UNLOCK Ambassador gunship - Complete level 3 of the helicopter flying mission. Diplomat heavy tank - Destroy the targeted buildings for the allied nations. MOAB bomb - Complete all HVT missions for the allied nations. Nuclear Bunker Buster - Complete the final contract mission, "Get Solano Part 2" to unlock it for purchase from Eva for $1 million.
When playing in Co-op mode with a friend, look in the same direction at the same time and throw the signal smoke to call in for reinforcements to capture an outpost. If timed correctly, both of the thrown signal smokes will start to smoke and two helicopters will appear.
In order to get 100% completion, complete the Outpost missions before starting the final mission in Story mode. The Outpost missions cannot be played after completing the final mission, and are required for 100% completion.
-After completing the first UP mission and receiving Ewan, speak with him about the Winch challenge. After completing level 3 on this challenge, bet the maximum amount of money. Even though you have already done this, the height will not raise. Continue betting the maximum amount and after about four times , you should have about $7.0 million. You can continue from here in order to get the maximum wager amount to $5.0 million when you have about $14.0 million in funds. Repeat as desired.
-Note: To save time, if you are trying to use the above method to increase your money, use stackable items from outside of your stronghold. For example, try the gas canisters across the road. Items used from outside of your stronghold stay in the exact location you put them until you quit your game, offering you a prepared stack height the next time around. Also, regarding the bet amount, once you go over $10 million, you only receive $1 million at first and slowly increases.
-Once you have acquired your helicopter pilot, he will supply a bet, wagering that you cannot stack enough things to get the toolbox above the displayed height. This wager is easy and the money goes up by about $2,000 each time you play.
-Find a Cash Bundle out in the field while making sure you are in an area with plenty of open room. If not, call in a helicopter and take the money to a safe area. Tag it and call it in. When Ewen picks it up and you are credited for the find, shoot the money crate. You can do this any way you want (for example, use a nearby armed combat chopper, wait for Ewen to get there, then shoot the crate after getting the credit). Money should rain down on the ground around you. Run around and collect it all for an added bonus of roughly $50,000. The bits that scatter across the ground are worth about $5,000 each.
Go to all the items you want to pick-up that are in range and choose them all. Once all items are selected, throw your resource pick-up smoke. The helicopter should pick-up one item, but all other items will disappear letting you know you have them.
An easy way to get cash in level 3 is to keep repeating the Winching challenge while wagering the highest amount possible. Stack the three crates in a pile with one on top of the other with toolbox on top. Wait a couple seconds and you will receive the money.
-When Carmona's men are attacking the PMC, after you destroy the tanks, set a charge of C4 on the gates closer to the mansion and blow it. It should drop straight down and block the road leading out of the compound. Enter the mansion and trigger the intermission sequence. When you leave the building, the road leading out of the compound is still blocked. Take out Carmona's bodyguards and his jeep should be stuck on the rubble of the archway. Kill him and snap the picture for easy verification of Carmona.
-When completing the mission on the oil rig in the water behind the PMC, kill Blanco and take his weapon--the hunting pistol. The hunting pistol is an excellent weapon, often killing enemies in one shot. With the hunting pistol in your possession, proceed through the "Finding Solano" mission/ After the encounter with Carmona inside the villa, he runs in a straight line directly away from you, giving you a clear shot at his back. If you miss on the first shot, he has a good bit of a jog until he reaches his jeep, giving you enough time to gun him down.
Note: This trick only works after getting a helicopter pilot and the winch ability. When on a transport or smuggling contract that relies on you not tipping the vehicle and losing the objects inside, summon a helicopter before entering the mission assigned vehicle, as close to the vehicle as possible. Then, enter the mission vehicle. Once the timer starts, get back out and take off in your helicopter. Use the winch to grab the mission vehicle and get as much altitude as possible. If you fly relatively level, you will not lose anything. However, even if you bank slightly to get around obstacles, losses will be minimal as long as you do not actually bank the copter in a hard turn. The vehicle will get tossed about, making the copter harder to fly; but if you travel directly to the drop-off point from the start, it will keep its cargo. This helps you avoid nearly all ground forces. All you have to worry about are the anti-air guns and other helicopters. If worst comes to worst, just drop the vehicle after coming down to about 20 feet or less. You will have already have saved enough time to hijack another helicopter.
To steal fuel tanks without being caught, fly a chopper used by the Faction that you are stealing from to where their fuel tanks are and winch one. The Faction will not attack you if you use one their choppers. Take the fuel to a neutral spot, and call Ewan to have it picked up.