The plug-in carpool.events is for all events for which the date and the place are known.
So there is no need to enter the city of arrival as it is already known: the place of the event.
With the plug-in you can integrate a carpool system into your WP site. Just enter [carpool:date:eventname] next to your events. Inscriptions are directly handled at the same page, inside your WP site. This is much easier for the carpoolers and they will not leave your site.
If you need a more classical approach like a platform/database with offers and demands you might be better of with another tool. https://www.blablacar.com? And someone told me Uber is doing something with cars too ??
Thank you for your feedback!