Different post-theme based on linked mp3?

Does anyone know of a way to detect if a post has a linked mp3? I want to modify the entire layout for that post to include soundmanager2 control and play. I could use the WPAudio plugin which scans the post for audio links and then adds the soundmanager2 control (class) inline but this does not give me the ability to change the look-feel of that post entry. Any ideas?

If there is no way to detect audio content in the theme then I’ll go hack the WPAudio filter as much as I can but it is a bit complicated because I want to also change some of the container classes and code for that entry, so I might need to walk the DOM and modify the post theme from inside WPAudio, which feels like an evil solution

thanks