It would be terrific for the domestic auto makers to regain a lot of their lost market share. However, Honda, Toyota, Nissan and other foreign makes employ a lot of Americans with assembly, engineering and marketing operations here. In addition a significant portion of the parts in American cars are produced outside of the US. Job-wise, the pickup we could expect from greater market share by American makes would not be as big as one might think.
I look at other industries like electronics and wonder why we can't produce more of that here. Flat screen TVs for example are produced (I believe) without a lot of manual labor. It would seem to me that products built with greater use of automation could be produced with less cost disparity. We've got to keep more cash right here at home.