I've often wondered why Mazda did not become a bigger player in the US market during the 1990's when Toyota, Honda, and Nissan all solidified their position here, but Mazda seemed to falter. I think I've discovered the reason, and it makes an interesting parallel to what GM is facing now.
Mazda thought 8it could increase it's sales by creating several different marques. In Japan they created Autozam, Eunos, and Enfini. Europe received Xedos, and North America almost got a version called Amati (an anagram of Miata). By 2000 none of these brands existed, Mazda focusing solely on Mazda, with the results being a stronger Mazda and increased sales.
Now, GM is not Mazda, by a long shot, but the lesson is the same. If you cannot devote the resources to a brand, there's no point in having that brand.
3 hours ago