I am not sure how these should be listed but I would think just G6 (except maybe the Concept)

we have 31 listed as G6, 1 listed as G6 Concept, 2 listed as
G6 Convertible and 1 listed as G6 Coupé.

Just trying to clean up some model names to make them more consistent.

Weren't the convertible & coupé seen as separate models? I do not know for US cars but for European cars usually such variants are listed separately by manufacturers.

I am not sure how the G6 was marketed (that's why i commented here and not on the page) But in my experience most US makers don't separate body styles into different models.

This does however bring up an issue with other makes sold in the US. I know I have commented on the Civic in the past as we have some Civics listed as Civic Coupe and some listed as Civic and then again no sedans listed as Civic Sedan. I have a very large collection of Civic and Ballade Brochures from 1984-1995 (at least one from every year) and Honda (in the US) does list them as separate models, each with it's own brochure. For Example at least for the years that I have brochures for they should be listed as:

Honda Civic Coupe
Honda Civic Sedan
Honda Civic Hatchback
Honda Civic Wagovan (84-87 US models)
Honda Civic Wagon (88-91 Us Models)
Honda Civic Shuttle (84-91 Europe)
Honda Civic CRX (84-91 US models)
Honda Civic del Sol (93-95 US)

I think I started to list the coupé separately because previously it was CRX, and also because Honda JP historic site separated it from the sedan/hatchback line.

That makes sense. I noticed that the 84-91 Civics had seperate brochures for CRX, Hatchback, Sedan and Wagon (or Wagovan depending on year) but the 92-95 list the coupe and hatchback in the same brochure and the sedan seperatly. I wish Honda would have been a little more consistant.