A nice way to travel with the car is to have a short break on a lössi. These are the costfree yellow car ferries here in Finland. The lössi to Bergö needs only about 7 minutes to get to the island, but is is a great experience.
Below is a link to the webpage of Destia. They provide the lössis in Finland. Click on 'ferryportal' to access the timetable search for all the finnish lössis (including the one to Bergö).