car ferry

Yes, but only in the direction Gudvangen --> Flåm (for some reason), and you must book in advance. There is more information here:

http://www.fjord1.no/eng/tourist-services/flam-gudvangen2

Read the bright blue box that is underneath the timetable. There is an 11:45 from Gudvangen every day, a 13:30 from June 20 to August 20, and a 17:40 from May 1 to September 30.

Another option is to ride the ferry to Gudvangen and back to Flåm, then to simply drive to Gudvangen. It will be a lot of time on the boat, but the scenery can't be beat! Good luck!

Sounds like good advice. That ferry must be heading somewhere else, not doubling back on this route. Of course, you can check again locally, in case the web site has an error. Happy driving!