I apologize for the late replies, but yea a bit later today when I get home I can send you the code. The way I went about it was I disabled control rotation, and then used Attach Component to Component to attach the camera to the scene component in the vehicle. Then once its attached I used Add Relative Rotation using the same Make Rotator values for up/down you used in the first image.
Then when moving the mouse left/right even with physics enabled and rolling the car over left/right mouse axis moved it up and down, and also allowed the camera to be rolled upside down.
Would you be able to send the logic you’re using to swap between the player and vehicle?