Prefer NOS if available, or nos condition. Original part # is 10078250. I have parts to trade if you need something.

Looks like it also fits some full size Chev/GMC trucks. https://www.ebay.com/p/6560...657f1771e3d0a0be64f1

FYI on Rearview Mirror Designs

I believe Fiero's came with two different mounting styles which the difference is the size of the 'channel' where the glued 'button' would go on the windshield.

Of course, the 'key' is the glued 'button' on the windshield; the mounting post glued to windshield can be 7/8" or 1" at its widest point.

From my '88 OEM Rearview Mirror:
Windshield 'Button' at its widest point is 0.970"
Mirror opening for the 'button' at its widest point is 1.0"

Check-out *this* 2023 thread for more infor:
Rearview mirror button and mirror opening measurement question/issue by Trinten
https://www.fiero.nl/forum/Forum2/HTML/147021.html

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EDIT

Brand-New GM 10078250 Mirror Assembly, Inside Rear View
https://www.gmpartsgiant.co...ror-as-10078250.html

GM 13524917 Replaces 10078250
https://www.gmpartsgiant.co...r-view-13524917.html

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Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles

[This message has been edited by Vintage-Nut (edited 04-02-2025).]