I like posting links, they dont lie. And the AA know what they are talking about ( apart from one meeting i attended when they started slagging alchohol. ).
http://shop.theaa.com/content/driving-in-europe
If you are getting an early ferry I would suggest a travelodge near the port, you dont want to ruin the experience by being tired.
I will get my mate to post up some info on ferries.
LEXX.