2. Scooter Brothers
Youtube is full of the kind of people you probably wouldn't want to sit next to on a bus. They have questionable mental states, they're probably not big fans of immaculate personal hygiene, and worst of all, they want everyone to be aware of them. Sometimes that self-promotion can pay off however, as the now infamous "Scooter Brothers" youtuber AutumnTheCuzzy will have found out when he discovered that Rockstar were not only aware of his hilarious/massively unhinged GTA IV video.... Not content with simply following an NPC around hurling mentally deranged abuse at him, the user - identified as Brad from FourPlayerPodcast - put on a baffling impression of Christian Slater from Robin Hood and shrieking his demands for acknowledgement and affection. That acknowledgement has now come in the shape of a cameo moment in GTA V (at least in spirit), when the player cuts to Trevor one of his random transitions has him following a scooter-riding NPC shouting that they are scooter brothers...
How To Find Them It's as simple as transitioning to Trevor until it happens - it's random, but you'll get there eventually.