Historically the American Cars and SUVs were different enough that it would be untenable to make them side by side. It's gotten better since the SUVs became mor

Historically the American Cars and SUVs were different enough that it would be untenable to make them side by side. It's gotten better since the SUVs became more car-like, but they haven't invested in modularity like the Japanese automakers, sometimes the companies blame unions for the inflexibility, but I think that's a red herring. However, it may be the case that the unions make it expensive enough to build modular lines that it's just not worth pursuing.