Greetings,
Finally replacing an original Mini Cooper Radiator cap. It has a metal smooth pressure plate and the throat of the water neck has an (old) rubber O ring. The newer caps have the typical rubber gasket on the pressure plate.

Q: Seems like if upgrading to a newer aftermarket cap, I should remove the original o ring sealer in there right? Otherwise we have rubber (old) on rubber (new). The plastic lip inside the neck seems like it would supply a good seal and the cap seems to go on with good enough pressure.

Anyone ever ponder this situation and run the cap without the 2002 style "O" ring?

Trying to eliminate the disappearing coolant issue we are facing.