I don't keep these kinds of things in my head...I use my two best friends Google and Wiki. :)
http://www.google.com/search?q=largest+%22containerized+freight%22++wiki
Mazda is owned by Ford, btw...Along with all of these other brands:
http://www.ford.com/en/default.htm
I say buy a MS3 and feel good about doing your part as an American!
[edit] Ford owns about 33% of Mazda - close enough for me.(usa)
Here's an article that compares several cars in that class...
http://www.edmunds.com/apps/vdpcontainers/do/vdp/articleId=117762/pageNumber=1
Search around on the Cobalt SS forums to get a feel for what their aftermarket is like, I think it is coming along fairly well though.
Of course, the...
Just curious, do you have traction control turned on? Do you get it when you rev the engine hard with it in neutral?
Do you get any scraping or just a clunk? Can your passengers feel the vibration too? I wouldn't be surprised if it's a motor mount...