The Scudero Fiero: West Florida's only Fiero club has posted a video with a quick and permanent repair for the wobbly/ lose manual drivers mirror control.
Its their first video and that shows but they are working on getting better. The next video will be a review and installation of the Black Top Racing wing nut repair kit.
Please like and give them feedback so they can do better.
Anyhow here is a link. There is a email address in the description that will put in touch with the man that makes the part.
Manual Mirror fix