Most ferry operators will allow you to travel with a rental car. Don't worry if you don't know the exact vehicle you're going to rent, you can enter an approximate size when searching for your ferry tickets. In the Vehicle Details section of the search engine select the vehicle type your intending to rent, e.g. Car or Van, and then a select a Vehicle Make and Model that will be closest to what you're going to rent. You can also select 'other' in the Vehicle Make drop down and select an approximate Length and Height of the vehicle. In the checkout you can enter the vehicle registration as ‘unknown’. Some ferry companies may charge you on arrival at the port to update the vehicle registration stored for your booking, but we'll let you know if this is possible before you complete your booking. You can also update the vehicle details prior to sailing in My Account.