Etruscan and Old Latin derive from Greek, which is a derivative of the Phoenician alphabet. The Phoenicians are known to have had a presence in ancient Iberia down to the Punic Wars and its very likely that their writing system was absorbed, partly or fully, by the natives there- later it was superseded by Latin, as was the case with the Germanic tribes (whose own runes were largely forgotten after Latin was adopted as the de-facto lingua franca).