[dagnabbitt]

As far as I can tell, the D29 option was for a style of mirror that appears to be West Coast Junior, but for one reason or another was cited as being slightly different from those mirrors that actually were called WCJ's. WCJ's of course have their own SPID code.

Perhaps the difference was simply that D29's were not chromed or not as fancy in their design, I don't know. The mirrors that I had on the truck were definitely original, though.

The Z49 code is as Canadian as it comes, and is on all Oshawa trucks. No idea what it includes, I would say maybe block heaters, but they have their own SPID code as well.

EDIT FirstOwner69 was posting at the same time as me, and said it better. Interesting that there were so many mirror options, even those of the same style and function.