Not sure how you are defining "dive". Just cheap and good, or does it have to have a certain character?
Some of the places listed above are great -- some of my favorite food -- but I don't know that I'd call them "dives" in my vernacular.
Swagger -- love them but it is a nice place with a fantastic beer and wine list
Vietnam cafe -- again, love the food but I don't see it as a "dive". it has a standard restaurant decor and atmosphere to me.
Grinders, BBs, Peanut -- totally agree with these
Papu's -- new to me, but I guess that's the shwarma place that steveb mentioned
If that's what a dive restaurant is, then I'll add a few:
Giovanni's Italian in Gladstone
Towfiq African in KCMO
Mesob Pikliz Ethiopian and Haitian in KCMO
El Pulgarcito Salvadoran in Merriam
Birrieria Michoacan in KCKS
Groove Station in KCMO
RJ's Bob-B-Que in Mission
Woodyard BBQ in KCKS
El Camino Real in KCKS