Convertible Car Seat Carrier

convertible car
A convertible is a type of automobile in which the roof can retract and fold away, converting it from an enclosed to an open-air vehicle. Many different automobile body styles are manufactured and marketed in convertible form.

seat
The roughly horizontal part of a chair, on which one's weight rests directly
a space reserved for sitting (as in a theater or on a train or airplane); "he booked their seats in advance"; "he sat in someone else's place"
show to a seat; assign a seat for; "The host seated me next to Mrs. Smith"
be able to seat; "The theater seats 2,000"
A sitting place for a passenger in a vehicle or for a member of an audience
A thing made or used for sitting on, such as a chair or stool