Wiktionary
car radio
n. (context radio English) A radio specifically tuned for usage inside cars, i. e. by utilization of traffic programme and alternative frequency functions.
Wikipedia
Car Radio (song)
"Car Radio" is a song written and recorded by American alternative hip hop band Twenty One Pilots for their second and third studio albums, Regional at Best and Vessel, respectively. "Car Radio" was released on YouTube worldwide on April 19, 2013. However, it was released as a single only on March 18, 2014. The video was directed by Mark C. Eshleman.
The song is seen as one of the bands most experimental, as it has no hook or chorus.