I don't think that's correct. As I read the Washington state ferries site (http://www.wsdot.wa.gov/ferries/sche...route=ana-sid), you can take a car from Orcas to Victoria (Sidney), but not from Sidney to Orcas.

Basically, you can take a car on the route as long as you don't get off until the last destination, but not if you're planning to get off mid-route (ie, anywhere in between Sidney and Anacortes.)

You do need to make reservations (and the reservations site does let you book a car from Orcas to Sidney): https://secure1.wsdot.wa.gov/ferries/webres/

All that said, your life will definitely be much easier if you skip the car -- the lines to get from Anacortes to Orcas via car ferry can be brutal.