It could've been Joe Estevez. He's not the most talented Sheen, but gosh-darn it, he tries :)
He did have that doof Sheen voice. :)
LOL I still think Charlie and Emelio are a hoot!
http://www.criterion.com/films/28051-repo-man
http://www.youtube.com/watch?v=fN2AXsF-kwc&index=5&list=PL0208BF8392B827AD