Couple Saves World's Oldest Operating Drive-In

A nice story about a couple that saved
Shankweiler's Drive-In, Orefield, PA, the oldest operating drive-in theater in the world...

Couple took out $1M loan to save America's oldest drive-in theater—now it brings in nearly $550K a year:
https://www.cnbc.com/amp/2025/08/16/couple-took-out-1m-loan-to-save-americas-oldest-drive-in-theaternow-it-brings-in-500k-a-year.html

So I was curious to know how they deliver the audio and visited their FAQ page. It's FM, - not surprising, but what did surprise me is that dead batteries are apparently occasionally still an issue at drive-ins. I thought that ended when solid state circuitry became the norm..
https://www.shankweilers.com/rules

• How do I hear the movie?
  Tune to 90.7FM! You can use your car radio, or bring a portable radio/boombox. Please note that smartphone streaming apps and bluetooth devices will not work.
• What if my car battery dies?                      This sometimes happens if you put your vehicle in the “run” setting instead of “accessory mode”. In the event of a dead battery, notify a snack bar attendant and we’ll jump-start your car during intermission or after the program