The other thing is the cult following that the civic has. and because its not a new engine there's already going to be parts for it. Our aftermarket is slowly building and every large company is quick to make parts for new hondas and stuff. Kinda sux
"Isn't that exactly what they did with the 5-door and 4-door models of the 3?"
Yes but thats the same carline. That's just a difference of civic sedan and civic hatchback. pretty much same thing.
As some of you have posted already (just reiterating) Mazda isn't going to produce two identical vehicles with only differences being exterior/interior(/price). That's causing a rift in your sales for the 6 considering the 3 will be priced at much less. The engine being used doesn't matter...