The linked article came up on another forum for an entirely different hobby: https://www.hemmings.com/blog/article/too-nice-for-tar/

I've been into Oldsmobiles for going on 30 years now, owned a few (nothing earth shattering) but haven't been active for the last 10 years. However, I've never even heard of the rear liners as even a rumor. Did I missing something? Were they planned on and never released? I personally see no use in them, as they sound like more cosmetic hassle then they'd ever be worth.
Help clear up the mystery please, with the vast amount of native knowledge around here. Guys such as Joe Padavano have more info rolling around in their heads than I'll ever have on this subject. I remember him from the old 442.com forums.

 

Pontiac offered them for the rear but Oldsmobile never did.
Welcome to the forum

 

Wow, the author of that article should have done a bit more research.
Red rear fender liner inserts for the 1967 W-30?
1968-1971 standard fender liners were metal?

Wow.

 

Yeah olds were always plastic in the 60 and 70s.
the w30 had red front no rears.
Only Pontiac had them on the rears.