The passenger door on my "new" P1 doesn't sit flush with the other body panels along it's rear edge. Is it possible to adjust the door lock position to pull the door in tighter?

Ta

 

Yes, you can adjust the door striker plate in horizontally,to bring the door panel level with rear wing,be careful not to move it too far in one go, only slide it inwards a couple of mm at a time,otherwise, you may set it in too far. Best look to see if the door has not been repaired as normally "panel fit/lines" are very good and dont normaly need adjusting, so may of been a visit to a bodyshop along the way.