Why am I yelling in my car?

I got up this morning with an agenda.  I knew that I would be spending nearly all day in my car.  But I wasn't unnerved by that fact, because I like my car.  It's a new car.  And (today, at least) it's a clean car that smells really good!  It's a car with a hands-free phone system, a satellite radio, and a DVD player (not that I planned to watch while driving--duh). 

I prepared for my day by grabbing a Diet Pepsi, my iPod, the GPS, assorted CDs, and my cell phone.  And for the most part, I was looking forward to a day alone in my car...  I sooo enjoy being alone in my car--nobody to re-tune the radio, nobody to tell me to turn it down, turn it up, turn it off...  I was prepared, and looking forward to my little road trip...

My hearts-and-flowers vision of the drive quickly dissolved into chaotic humor.  I didn't get far from home before the GPS started yelling at me.  And I don't mean talking loudly, the volume was set at 100%, it was yelling!  Unfortunately, at the same time the GPS started yelling, I was also voice-dialing my mom.  My car then started yelling at me...

That command is not understood.  Please rephrase!  

Of course my car couldn't understand!  While I was saying,

Call Mom, 

the GPS was yelling,

Turn Right in 50 feet! 

And I found myself yelling at everyone to Shut Up!  Of course, by everyone, I mean noone...  I was, as you recall, alone in my car...