We are huge fans of Brittany Ferries (no personal links); having now taken the 4/4 on 8 return journeys eiher to France or Spain. In our experience, they take exceptional care of "classic" cars. Photo below was taken by Jays when boarding at Portsmouth, en route to the 2012 Le Mans Classic. (Note the lovely Lotus VI in front of Jays car - our 4/4 is the regal red one)