If we can go outside the US... I humbly submit the Nissan Tsuru. A econobox that was nothing more that a casket on wheels. The NCAP has reported that the Tsuru was involved in more than 4,000 deaths in Mexico between 2007 and 2012.

https://jalopnik.com/horrifying-crash-test-against-a-modern-car-shows-why-me-1788423100