[1] Ironically, Flint (infamous for its OTL environmental crisis) is one city that may benefit greatly from this scenario. In 1960s, it was home to the second-largest base of operations for GM, thanks to the decentralized management structure of GM at that time. According to one source I found (“GM Building to Get $10 Million Modernizing”, Detroit News, June 3, 1971), there were rumors in the late 60s that GM would move their HQ to the Tech Center in Warren.
[2]
https://en.wikipedia.org/wiki/Flint,_Michigan_auto_industry#Buick_Motor_Division
[3]
https://www.who.int/ionizing_radiation/chernobyl/backgrounder/en/
[4]
https://en.wikipedia.org/wiki/General_Motors_Building_(Manhattan)
[5] At the time, Ford, Chrysler, and AMC were located in the cities of Dearborn, Highland Park, and Detroit, respectively. The latter two would eventually move to the suburbs of Auburn Hills and Southfield.