Detroit must be mentioned close to 10 times in one way or another throughout the series. Business trips, families moved to, people coming from and so on. But always in high regard with implied reverence for its integral position in the country's economics and industry. The foreign influx of cars hadn't hit the country yet devastating Detroit. Now Detroit is more known for its high crime rate. Definitely different times.

I never thought about the number of times Detroit is mentioned. The one episode that stands out for me is Convicts at Large. I know Siler City is a far-cry from Detroit, but it has to be mentioned at least 10 or more times as well.