Noticed this when I was flushing the old brake fluid out. Left over from the Renault days I presume. Chrysler/AMC/Renault/Daimler/Fiat with a few Aisin-Warner parts is an interesting duck. They had the new (to us) Fiat 500 under the same tent as Jeep at the MN State Fair this year. I miss the LeCar.

 

Perhaps a special New Orleans cap?
Actually probably a reservoir for Canadian maket, both language lables required here.