This is the 1969 Siata Spring which we all know so well.
The car was introduced in 1969 as "Beat" but that name did not last.
The images from magazines (Quattroruote):
I have letter from the importer to the dealers and a "folder" for you too; click on the letter to enlarge
Siata built some other Fiat 850 derivatives too:
The rear end looks a lot like an Opel-rear.