Or you could turn on the radio and let the DJ change the records for you.
You mean let the DJ change the commercials for me? Radio sucks.
I have thousands of songs in my iTunes library available to stream from the cloud. Why would I voluntarily listen to commercials and garbage pop radio songs when I can listen to whatever I want through my phone? That's just dumb.
Being able to control the music with Siri so I don't have to take my eyes off the road is an extremely useful feature.