does anyone know if the 88-91 wagon ever came with a passenger side mirror? i have seen a couple with mirrors but i am unable to find the part anywhere online. i know most didn't but i know they exist.

 

Yes they did, but as you noted they are very difficult to locate. Check out HondaCivicWagons, one of the members on their sold a couple a while back on ebay.

I just took one from a DX and grafted it in. However that takes some work with a dremel tool and stuff. I would recommend getting one from an original, if you can.