Right...?
From what I understand, the Pentastar was used from 1962 until (around) the mid '70s and only appeared on the lower passenger side fender throughout Chrysler's product line. And yes, it was also used on individual parts as well. The use of a symbol for brand identification was a marketing ploy to help boost automobile brand identity. Recognizing a symbol is much easier than reading text, so, a symbol it was. And by placing it on the cars passenger side (read, curbside) meant passersbyers would see it as they walked down the sidewalk. Passive and subliminal marketing at work.
This practice harkens back to the early days of the automobile when coachbuilders would place their logo on the sides of cars to be photographed along with their celebrity owners/drivers/passengers, increasing their brand status - no different than today's influencer marketing on social media or product-placements in everything from movies & TV shows to newscasts and sport events.
As for why John's car didn't have one and mine does - or why his Dad had one on the driver-side - who knows? But now you know a little more about why it might be there in the first place...
