Friction wielding?
 

Seem like Mazda has develope a method to wield aluminium and steel together to save wieght, with friction. This is supposed to be used on the MX-5, anyone knows if they try it
out on the 8 as well?

Yep, it's called Friction Stir Welding (FSW). Very cool stuff. We are looking at using FSW to weld floor panels for the C-130J a/c. Check this out.

http://www.aluminum.org/ANTemplate.c...ContentID=7156

Mazda actually began using the friction welding technique to weld aluminum sheetmetals on the 8, and then they improved it to enable steel-aluminum friction welding on the new MX-5