Playing Old Car Talk episodes on my iPhone

I've been wrestling with this for a couple years even in this venue so I thought I would try again now that I've somewhat isolated the problem. Over the last 10 or so years I've been listening to episodes of Car Talk. Originally I listened on an mp3 player to an ipod then to an iPhone. If I go to iTunes on my desktop and list the Car Talk episodes it shows over 150 of them, and I can listen to them on the computer in iTunes. Of coarse everything now is called a podcast, but back then that was not the case. These episodes of Car Talk are not included in the Car Talk podcast downloads which they now title "The Best of Car Talk". I want to listen to the Car Talk episodes from 10 years ago, but they are not recognized by the podcast app on the iPhone so I only get recent podcasts. Is there a way that I can listened to these episodes on my iPhone with the podcast app or otherwise?