Shotgun rider means: You can let your girlfriend sign your name on your front passenger seat, thereby binding your ownership. (in Community Dictionary, added by Donato Vega)
What else does Shotgun rider mean?
- This word is most famously found in Tim McGraw’s hit song, “Shotgun Rider”. It refers to a person’s best friend, partner in crime and person who rides shotgun in their car the most. They can always pick up right where they left off no matter how much time they spend on a particular part or what their life has thrown at them. He doesn’t want any other shotgun rider to join him. (in Community Dictionary, added by Victorio Cambil)