I have a feeling our family beater (aka my pfp) could qualify for this list, despite being a Civic. It was awarded the Japan Car of the Year when it came out, but any of the marketability was neutered by the debut of the Fit, and despite being the standard color I can count with my hands the number of times I've encountered this car with the same color in the last 20 years....

Mmhhh, there are masses of models missing, for example the failed Wankel-trials M35 and Birotor by Citroën

- or my Dodge Durango

As the dealer (and importer before) told me, in 2013 only 30 SXT with R/T engine and low spec trim (no GPS, no entertainment system, no badges, luggage boxes instead of a second back seat row) were made - as civil patrol cars for Argentina' border police.

But Argentina had annother national bankrupcy and couldn't pay them, so for 1 1/2 years these 30 Durango were standing in Chrysler's backyard, until this dealer bought them, shipped them to Europe, pimped them with features to pass the EU-registration and sold them.

It has not only
https://youtu.be/QTOg4aYGtdY
but also a certified cop tachometer and an extra red interior light.

P.S. the cop tachometer has a disadvantage: when you were flashed by a speeding camera, you can forget the hope "It wont be that bad, because you weren't that fast as the tachometer shows it"

Here are some of these Rarest cars ever made by famous automakers which does includes SAAB Sonnet I here