Yep, we say bags too.
Interesting though - just asked my 16yr daughter and she answered “dibs” and “shotgun”.
Actually, this is not true. The passenger seat in Japan is called the “assistant’s seat”, which is a literal translation of the Japanese “joshuseki”(助手席), which is a lingo carried over from the taxi business.
It came to be named this way in the Taisho period when taxis started making their appearance in Japan. The vehicles were made overseas and were large and had high ground clearance which made it difficult for the relatively shorter Japanese to enter and exit the vehicle, especially when you consider that the regular garb in those days was a body-restricting kimono. It was the “assistant’s” job to help customers get in and out of the car, and as this person sat in the passenger’s seat next to the driver, so the name stuck.