This is your standard car player (FM/MP3/CD) that you slot into your car.
However it also has a cheap 0.5w or more CB radio circuitry included, so that you can communicate other cars close by. The reason it is cheap, is that instead of a seperate CB antenna, it uses the FM antenna of the car. This
admittedy will not have the same range as the more professional car radio, however it is much more easier to install. (And still will be useful in a family convoy situation, or simply crusing on the highway)
The benifit is that it would encourage more casual users to install a CB radio into their car. Increase usages of the radio can be assisted by showing on the display of the radio, what each channel is generally used for (e.g. channel 5 is standard for emergency)
In addition, you can use the entire car speaker system as your CB speaker, saving money from having to buy a CB speaker. A seperate Push To Talk mic may be needed, but you can always press the red button on the player and speak to it (As the player has a mic embedded as well).
(Oh and if we are going to make CB radio for in car use cheap and easy to install, then might as well also provide support for "CB paging". Short burst of text messages, for those who feel like sending alerts to nearby cars.)