This fascinates me. Is the Etruscan language related to no other? Too bad we don’t have a Rosetta Stone for it.
There are theories ranging from the Basques to the Trojans, and the predominant opinion is that they migrated from Asia Minor sometime in the late 2nd Millenium BC. There is no widely accepted linguistic relative to Etruscan.
It is strange that no Latin/Etruscan documents have been found, since Roman culture was so widely derived from Etruscan culture, even to having had Etruscan rulers. I am sure such documents existed, the problem is that no extensive stellae existed at that period in Rome or Etruria, and any other writings in that climate would be unlikely to have survived for 2500 years. Hopefully such a document will eventually be found.