Which is odd, considering iTunes, Windows Media Player and even Xbox 360 and PS3 will rip CDs.
It does make a difference whether the primary purpose of the device is to rip CDs. But I believe the real reason they didn't go after those devices is, that there may not be enough money to go after.
The devices you mention probably cost less than 2500$ per unit. A car could cost significantly more than 2500$, so it would be a lot easier to squeeze 2500$ per unit out of a car manufacturer.
That strategy could backfire if in the end the question about the primary purpose gets applied to the entire car and not just the CD player. I don't think they'll manage to convince the court that the primary purpose of the car is to rip CDs.