Glad you got it working! As far as the hiss goes, it could be a weak ground, or maybe the gains are turned up too high. Try adjusting the gains on th eamp first, and if that doesn't work, thry moving the ground to a different location.
We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.