Now when you press the combination G + B, Karl will call and call for paratroopers to help. After the call, you will see a cutscene of them parachuting. Then they will follow you and protect you from enemies. They are armed with M4. If there is no space in the car, they will steal other cars and follow you.
There is also a version with members of the Grove gang. However, if Emmett and Sweet die, then all the gang members will disappear.