Asa a lot of other people, I have the problem of how to spend the time while I am in the car. Well, of course, the first thing to do -as everyone says – is to drive. With all the needed attention, obviously.
But, while you’re driving, you may also use your ear to listen to something.
Yes, music is the first choice. It has been my first choice for many, many years. But sometimes you want to be exposed to something that is not exactly musical, in a strict sense. There is a lot of richness, out there.
You can embrace podcasting, for example.
Podcasts are wonderful when you’re driving.

They are made often by speech, and are not so loud and invasive as – say – death metal music, so you can hear the sounds outside your car. Which can be a very good thing, if you’re driving (after all, the world outside claim your attention).
One thing I appreciate of Spotify (among others) is that it includes a section devoted to podcast. Which is not automatic, for a streaming service (for what I know, Google Music features no podcasting yet).  Unfortunately, not all the podcast are present inside Spotify, so I must rely on a dedicated app if I want to really have access to all the richness out there. I have chosen Pocket Casts because, while it’s not free, for a small amount of money it gives you an endless river of possibility and you have the real chance to configure an environment exactly as you like.
Oh, and another possibility is given by audiobooks, of course. Admittedly, I am a not so avid consumer of audiobook and, as occasional listener, I do prefer not to rely on a monthly subscription, as possible with Audible and similar services. So I take advantage of the audiobook section of Google Books, which it’s perfect for anyone who likes audiobooks but do not want to add another regular channel of expense. 
Granted, there are plenty of possibility to explore to make the way home (or work) less boring, in case of heavy traffic. But, to be honest, my really preferred choice, it seems not available yet…