Pasadena police said gunfire erupted just after 7 p.m. near the eastbound 210 at Lincoln Avenue. The shooting appeared to take place on an on-ramp.
The victim then drove to Huntington Hospital to be treated. Video from the scene showed the car, a Dodge Challenger Hellcat, near the entrance to the hospital as its blown-out window was on the ground beside the car.
The condition of the victim was unknown.
Further details, including a suspect description, were not immediately released.
The California Highway Patrol is handling the investigation.