Your dad is correct. When you took your foot off the gas, it would shift into High Gear and you would hear an audible “Click”. My sister had one and I remember it well Your dad has a good memory. As I remember my sisters car, you could shift the (three on a tree) in the normal fashion,OR you could just leave it in the Third Gear position. When you came to a stop. The gearshift lever stayed in the third gear position but the car would start off in Second Gear. Then while underway, lift off the gas and “click” you were in third. Never had ton use the clutch. (Clutch was to get into reverse and to get into First for the first time).
(My first car, a used 49 Chevy was faster - yes I’m old but still have good memory).
It’s been many years since he spoke about the car and he passed away a long time ago. I can’t remember if it was a ‘49 or a ‘50 but I seem certain it was a Windsor Coupe. Black.
He mentioned several times that it was the best car he had ever owned. I had to do some searching on it. Chrysler called that transmission the PrestoMatic.
