i think the symbology of a logo can be a nice by-product, but at the end of the day the function is to brand. in fact i would say that the GM logo has symbolically about as much meaning as the audi 4-circles, albeit using a different language. 'GM' stands for 'General Motors'. it's a rather pedantic symbology, but still it's pointing to something. more important, it's very recognizable. having said all that, i think GM's is really pretty boring compared to many other car logos. and i really don't like that fake chrome reflection effect. that kind of stuff on a logo just looks cheap to me.