just so there isn't confusion: the songs on ocho that were later on songs of inaudible trucks and cars are different versions. I'm never sure if people who haven't heard it are realizing that fact or not.
As far as I know, and I'm inclined to believe that I would know, Cuatro has never surfaced on the internet, only Ocho. As far as I know, Cuatro was alternate versions of four songs from Ocho, so it's probably nothing that we can't live without.