It's weird seeing Chevy Chase in a role post-Community, I thought he'd just disappeared. I feel like I wandered into the Worst DVD Covers thread after looking at that poster.
This appears to not be a 4th film in the series, but rather a meta-film about Paul Hogan playing himself. IMDB synopsis: "Paul Hogan is reluctantly thrust back into the spotlight as he desperately attempts to restore his sullied reputation on the eve of being knighted."