Classic/Antique Car Repair: Car Radios 30s to 1941- reference, kfi los angeles, car radios

Question
Hi, Mr. Benjamin

My question may seem out of place or odd, but since you are a mechanical expert for vintage cars I was hoping you could help me anyway.

I'm a writer and the story I'm working on starts in 1941. I want to use the car radio as a means of telling the characters about Pearl Harbor etc. But I don't even know if car radios were prevalent or available in cars back then (30's and later).

So far the references I've found don't really make it clear if car radios were common enough that a number of drivers would have one.

Sorry it's not a tech question, but I've been looking and asking everywhere. You certainly would know more than I do.
Thanks for your help.  

Answer
Well, you've lucked out because I not only operated an  auto shop late in life, in my main carreer I was an electronics engineer, and worked for one of the major auto radio manufacturers (Philco) during my college years (early 50s).   I also play with antique radios, including auto radios!

The auto radio was very common by Pearl Harbor. They first began to get popular in expensive cars in the 1933-34 time frame, and spread to the lower priced cars as the 30s progressed.  By the time of Pearl Harbor (which I remember clearly, by the way) the car radio was available in all brands and models of cars, and also was a popular aftermarket accessory, costing just a few dollars at Pep Boys.  Of course this was 99% AM only, but there were very powerful radio stations all across the country by then - you could hear KDKA Pittsburgh, KOB Alberquerque, KFI Los Angeles etc. over most of the country.  If you want a specific area's main radio station call letters, post a follow up question to me, I happen to have memorized many of them (I was fascinated by radio as a kid).

Dick