We know that CIA was looking into infiltrating the embedded systems in vehicles since as early as 2014, thanks to Wikileak: https://www.caranddriver.com/news/a15342464/cias-alleged-for...
One year before that, in 2013, the death of Michael Hastings was incredibly suspicious and matched what one of these assassinations would look like: https://en.wikipedia.org/wiki/Michael_Hastings_(journalist)#...