Greasy Fork

The original video doesn't autoplay anymore, so you just hear the one.

Okay, I had to do a lot of debugging. Now, it replaces the original YouTube video player with an autoplaying iframe video, which autohides via CSS and inserts onto the page.

Note to self- always test userscripts BEFORE uploading. The previous version infinitely redirected links; now this has a failsafe so it only redirects once per new link.

Check my Spotify button remover script's update for the details.

Changes the script icon for all you light or automatic theme lovers (I'm the latter).