I've been looking around the internet and looking at brochures and such and so far I haven't found any sales literature that included K as part of the model name. these cars, though, did have a "K" badge next to the name on the rear. This was done by Chrysler so that people would know more about the K platform. But I don't think that "K" was actually part of the model name. Many people have probably confused it because of the "K" badge.

Point is, K was the name of the platform. But I suppose that taxiguy might have some more information.