An unexpected feature
 

I have never heard of this before; has anyone else had the same experience?

While driving, I listen to a station that has three transmitters (two FM, one AM) in neighboring cities. They all have the same call letters, but different frequencies, obviously. My car switches automatically between them to stay on the strongest signal.

Even though it is only a 2006, it is the most modern car I have ever owned, or driven; am I that far behind the times, or is this some undocumented feature of owing a Porsche? Everyone I mention it to thinks I am nuts. Of course, most of them think that even if I don't mention it.

your car must be possessed

Voodoo, I say

"your car must be possessed"

Or I really am nuts.

I bumped into the engineer for the stations, and asked him about it. He said the stations are broadcasting a digital watermark (called Radio Data System), specifically designed to do exactly that. It also enables your radio to display what kind of programming you are listening to.

Here is a Wikipedia page about it: https://en.wikipedia.org/wiki/Radio_Data_System

Witchery, I tell you, pure witchery.