I don't just mean for GM - I mean for all brands.

I'd really like to be more educated in terms of what cars share what platforms and what, if anything, is different from one to the next. I've been able to find tidbits of info using google, but it can be a drawn out process with not always conclusive results.

 

wikepedia, I guess but anyone can fill that information in so you nevere know how right it is.