Jalopnik asks, "Why Do Republicans Hate American Automakers?", and talks about how some Republican pols are badmouthing GM and Chrysler, including recent presidential election loser John McCain.
Anecdotally, however, I can tell you that many Republicans are solidly "buy American" types, from a variety of different backgrounds. There are rural farmers and hunters who love their full size American trucks. There are patriotic war veterans who won't drive any "Jap" cars. And, believe it or not, there are even Republicans who are pro-UAW (though a minority, for sure).
I have personally noticed that there are lots of liberals who drive non-UAW assembled vehicles with pride. Many times I have noticed a car (in metro Detroit, no less!) sporting stickers such as "Obama", "End This War", etc., and as often as not, this car is a Toyota or Honda. It seems the liberals don't necessarily love the American auto makers either, at least not when it comes down to choosing a car to own.
When was the last time you saw an NRA sticker on a Prius?