"An Old Oriental Gentleman I know has been kept hostage by some South Americans in Aspatria. They're trying to extort additional funds from me, but I don't believe in renegotiation. A deal is a deal..."
Realizing that the only way to enter the compound is by entering with a Cartel Cruiser, Claude goes to Fort Staunton, steals one, drives to the compound and is automatically allowed inside the compound, but is quickly recognized by the Colombians. Claude quickly reacts and takes all the Colombians out before finding the Old Oriental Gentleman in one of several garages (in each of which at least one Cartel member is hiding). Once all the Colombians are dead, he gets in a car with the Oriental Gentleman and takes him back to Donald Love, completing the mission.
In order to complete the mission the player must:
Go 'jack' a Columbian gang car, so you can infiltrate the hideout, head north and you'll find one in Fort Staunton
Rescue the Old Oriental Gentleman
Take the Old Oriental Gentleman back to Donald Love's building
While it is possible to enter the Cartel compound without a Cartel Cruiser by jumping over the gate using a large vehicle, the compound remains empty and non-interactive until the player is driving a Cartel Cruiser.
An effective method when killing Cartel members is to simply run over half of them using the same Cartel Cruiser the player used to enter, to the point the vehicle is badly damaged from gunfire and the player is required to dispatch the rest on foot.
When dealing with Cartel members holed up in the garages, the player may benefit by using a shotgun. As the garage doors will only open when the player is close to the door and also the hiding Cartel, players may sustain more damage due to close-quarter gunfire, thus requiring the players kill them as quickly as possible; shotguns can easily deal a single-shot kill, ensuring minimal damage to the player.
Another method is to stay at the gates then kill all enemies in the screen with the sniper rifle then enter the garage and kill the last two or three enemies with your vehicle.