German automakers formed a secret cartel in the ‘90s on diesel emissions(washingtonpost.com)

https://www.washingtonpost.com/business/technology/german-automakers-shares-fall-on-diesel-emissions-concerns/2017/07/24/f86399f0-7065-11e7-8c17-533c52b2f014_story.html?utm_term=.a3994a27a148