jason should be kinda boring
Everyone wants Jason to secretly be wild, undercover, a genius, related to somebody, or hiding a giant twist. I hope he is just some guy who is good at driving and makes bad choices because Lucia looked at him.
GTA already has loud personalities. A quieter dude getting dragged deeper into increasingly bad plans gives the story somewhere to go. He can still be funny without announcing a huge gimmick in his first scene.
Make his special skill something basic too: better focus behind the wheel, quicker item swaps, maybe he can keep a damaged car under control after a tire blows. No superhero vision.
Normal people become interesting when the plan goes wrong. Jason does not need a wiki twist before we even like him.