To get into and out of vehicles, while I’m not certain of the exact systems, will require heavy blueprints. I would think that a vehicle pawn and a character pawn blueprint for the individual movements and utilizing the bone structure of the car to allow the player pawn to attach to the driver seat would be viable. After that it is primarily animating the player character to get into the vehicle and switching control from the player pawn to the vehicle pawn.
I followed the blueprint and it works great for single player. When the player leaves the car on the server, the pitch and roll get reset. However, when the player leaves the car on the client, the pitch and roll are not getting reset. This doesnt really make sense to me because the character is properly being spawned at the Spawn Location arrow on both the server and client.