Semi related question: we’re doing something similar - flying to Seattle, renting a car, driving it up, parking at the port during the cruise, then driving it back to Seattle. I made my reservation at the port but the website requires the car and plate info. Obviously won’t have that for a rental car until we pick it up. I put “unknown” in all the fields and the system accepted that. I emailed customer service to see how I should handle this (I know when I make a parking reservation at my local airport, they say the plate info is just in case you lose the confirmation so they find it in the system). They told me to reach out again when I have the car info. Except I’m arriving on a Saturday when their phone lines are closed and email response takes days. I looked online and it looks like I can just add the rental car to my profile when I have all the info and swap out the car on the reservation? Or I can walk over to the port when we get to Vancouver and talk to someone there. Has anyone had experience with this situation? I imagine it happens all the time.