It seems that nobody saw him, but this was the car of "wggarrido" (http://imcdb.org/profile.php?id=wggarrido)
http://imcdb.org/vehicle_196819-Siam-Di-Tella-1500-ADO9A-1962.html
They told me on facebook (I have added), it was his car. Now, is owned by a friend of his, and belongs to the club of Siam di Tella.