Yeah, exactly...the only reason people talk about it is because it has, what do you call it...male cleavage?...which could be nothing more than age sag, bolstered by the framework of the clothes they put on him.
If you ask me, it doesn't look much like rubber, especially considering the time frame of the movie.
http://www.briansdriveintheater.com/beefca...omontalban9.jpg
Him when he was a lot younger.
http://www.briansdriveintheater.com/beefca...montalban13.jpg
http://www.briansdriveintheater.com/beefca...montalban14.jpg
Edit: Sorry, I get obsessive...at least I know what the edit button is for...better pics from the movie. If it's plastic, it flattens out nicely when he leans back...