Thanks Jim, I have searched on Amazon and other places, but so far, no luck. It looks like the one you found is made for a different style male end (are we still allowed to say that?).
Ulix, Dr Jeff, yes one is German, the other Italian - Porsche and Maserati. For some reason the female end is larger on these cars, my car charger male ends are too small to fit snuggly. Right now I fold up a piece of paper and jam it in there to hold the male end of my charger in position.
And no, I am not going to install an add-on outlet in either car.
I suppose some sort of ring to fit over the OD of the male end of my charger would work? But I would prefer to just find a charger with a larger male plug. I'm surprised this isn't a well known thing. I suppose I'll post on a Porsche or Maserati forum?