A USB computer port in your car might seem strange, but it offers an inexpensive and easy way to listen to your music library without having to deal with an MP3 player.
Flash drives, also called thumb drives, are relatively cheap and easy to use. A 1-gigabyte thumb drive can hold up to 250 songs and costs under $20.
Just plug it into the car's USB port - the 2008 Cadillac CTS, for example, has one hidden inside its center storage console - and you can sort through the list of available songs, albums, artists and genres using the same information screen you would use to control the radio or listen to CDs.
Some cars also have a slot for a flash memory card, the sort you might use in a digital camera. You can use those in the same way, but a thumb drive is easier to carry and more rugged.
It would seem inexpensive for a car maker to add a USB port, but to be useful these ports must be hooked up to a fairly sophisticated computerized stereo system, and those aren't cheap.
