Not as evil as it sounds!
This is for a corporate deployment tool. One of the things they want to do is to manage browser add-ons & plugins. UI wise, the client considers it inappropriate for a dialog to pop-up.
What I need to do is copy out xpi files to the destination systems, but how do I trigger an install.
install-global-extensions polls the user to ask permission for the install.
obviously windows, in a very uncool move, install FF add-ons without polling the user. So it's possible