Will Internet Radio eventually Kill In-Car Traditional Radio? Yes, but…
…that is your playground, too.
As this NYT piece notes, Internet Radio is fast coming to a car near you. Sure, it's already here if you don't mind a few dangerous distractions and a stray cable here or there. But that doesn't describe most people.
Penetrating the in-car market in a significant way will depend on two key factors:
1. Ubiquity
That is, the service has to be available widely in a way that's recognized and widely acknowledged by consumers.
And "ubiquity" also means receivable everywhere (or at least everywhere that matters). The spotty nature of high-speed coverage is well established. I – and pretty much everyone else – expect this only to get better over time, however.
2. Simplicity
Indeed, the biggest advantage of radio is its utter simplicity. Nothing is easier to use.

Without question, traditional radio will be part of the "entertainment console" and integrated with its new competitors on an equal footing.
Given the importance the in-car environment has to radio, this is all a very big deal.
So what does this mean for all you traditional broadcasters? Two things, whether you like it or not:
1. Unique and attractive and compelling content will keep people's ears pinned to your content, regardless of how it gets into the car. Are you investing in this?
2. Broadcasters who don't dive into the digital future with both legs will eventually find those legs chopped off under them. Not only should you be streaming, but you should be streaming things you're not streaming now.
You should be providing new options to your existing audience.
Before somebody else does.