virtualbox.org

Host OS is Arch. I've tried a few guest OS. In every case the guest addition iso is missing and when I select the upgrade option it tries and fails to download. I've read the manual. It says the guest additions iso is in the installation directory. I've looked manually and used search tools. I can't find it and I can't find a link to download it. Anyone have any idea where I'm supposed to find it?

This is probably happening because you're using the Arch fork of Virtualbox instead of official Virtualbox from https://www.virtualbox.org/wiki/Downloads which always has the Guest Additions ISO bundled in the installation folder. The forks force a separate download of Guest Additions.

You can download GAs ISOs individually here: https://download.virtualbox.org/virtualbox/

Thank you very much! I really appreciate the help.