Being flexible is important, which is why we offer free cancellations on most car rentals. If your St. Louis Aquarium at Union Station plans change, just log in to your account through the
Trips portal, select “manage booking” and then choose “cancel this car.” Flexibility is just the beginning of the reasons to book a ride with Expedia. Bundle your hotel, airfares and vehicle rental into a vacation package and save on your entire escape. And that means more cash to spend on having a great time!