I know I'm late to the party but I just got GTA5 for Christmas this year (2018) and I'm just seeing for the first time what this amazing game has to offer. Since I enjoy single player game play and since I need to learn so very much to play GTA5 successfully (not to mention key binds), it just makes sense to explore the modding world along with the game.
My most recent discovery is JOIN ME PEDS, a compact little script that gives you up to 7 buddies who will protect you and fight alongside you. The mod is customizable in many ways to give you flexibility with your minions. You can choose NPC's to invite into your squad or you can press a hot key and have all seven slots fill up automatically. Read this that you can pick all big guys for your squad or all bikini clad women with fire in their eyes. It's your squad.
Your buddies will join you (however reluctantly) in your vehicle and if there aren't enough seats, they'll get their own ride. If you fire on someone outside the vehicle, your buddies will lay down supporting fire. When you exit the vehicle, your buds will be on your tail and protecting you.
Now to an amazing experience. If you long press a hot key, you can become a passenger instead of the driver of a vehicle populated by your buddies. That means one of your recruits drives the car while you sit back and partake of whatever celebratory libation you enjoy. I found it incredible to watch the AI drive this vehicle to the destination I've specified. Mind blown!