Comment by ElevenLathe

Yeah I understood it was about the make of GM car, hence the thought that its likely in Southeast Michigan (aka Metro Detroit) somewhere. At one time Pontiac Division (of GM) had their own engineering which AIUI was actually headquartered in Pontiac, MI (aka in Metro Detroit). IMO it only makes sense to send an engineer out at supper time for a week or more if the engineer is in the same metro as the letter writer, hence the assumption. I doubt they would have sent the engineer to Italy for that long, but maybe I'm wrong -- midcentury America was a land of lavish expense accounts!

Anyway we can speculate all we want (either about the location of the original story or about TZubiri's cryptic reply) with any satisfaction unless somebody has some new source of information, so have a good day.