As promised:
https://www.origin.com/swe/sv-se/game-library/ogd/OFB-EAST:48204/extra-content
This is the swedish one but just go to your preferred language and you'll get all the add-ons. The addons will load in your language of the game regardless. I use international english ver of Simcity 2013 and here everything worked.
The only add-on you want to download if you get the complete edition of Simcity 2013 is Nissan Leaf. Its free.