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antp
I think we included it when the model name included "concept" in its name, which sometimes happens.
But some may be wrongly listed.
Though that it allows to separate them from the production vehicle in the listing.
t0nkatracker
I was looking through some of the Concept Vehicles on this site and noticed that some have "Concept" listed after the model name and some don't. I think it is pretty redundant because they are already listed as Concept in the class. Either way it is done I think it needs to be consistent.