being a Belgian I can advice you to go to Boulogne and the Cap Griz Nez and the Cap Blanc Nez.
More interesting, better food and better roads.
There is lots to see in Belgium, that is true, problem is they left no place for nice road

Roads can be rough at the French coast also but at least they have twists. As were Belgian roads are straight and have bad road conditions!
Here are some pictures of that region: (Boulogne)
http://www.schoendoos.be/Photoshoots/2007-07-21/index.htmlVisit little towns like Wissant and Wimereux and have a meal in the old city part of Boulogne and you will not regret your trip!