Originally Posted by Lando25
I've been looking for the merryweather JK for a while with no luck.
There are 2 missions where you can get them in single player. As for GTA Online, you have to do the mission called "A Titan of a Job" where you have to steal a cargo plane from a hanger guarded by Merryweather. Once you get inside the plane, reinforcements arrive to stop you and they are in the Jeeps. You just gotta be sitting in one when someone else drops off the plane at the other airfield.