Complex sentence: The most notable thing he auditioned for during that period was the role of Eddie Valiant in Who Framed Roger Rabbit, he was a finalist for the role when the director couldn't get any A-listers to accept it.
Split into simpler sentences: The most notable thing he auditioned for during that period was the role of Eddie Valiant in "Who Framed Roger Rabbit". He he was a finalist for the role when the director could not get any A-listers to accept it.