Micah and I love road trips and surprisingly we do really well in the car. We've even made it 19 hours in one day! When we do go on vacation we're C-H-E-A-P! We bring a huge cooler with food that we can make throughout the trip and always bring a grill. For the actual road tripping part we love this sandwich. I make it before we leave and wrap it in some parchment or wax paper and they're so great after sitting a couple days. The olive oil begins to seep into the bread and the flavors just meld so much better.
Now you'll have to decide what kind of bread you want to use. My dad raised me on breads with hard crusts. He always said that it wasn't good bread unless it cut the roof of your mouth and I totally agree. Micah on the other hand, does not. It's up to you but Rachel suggests a crusty bread. I'm sure you could make this with some good quality canned tuna but I always make it with the tuna steak.
I don't have any pictures of this but I made it when I went camping last month. They worked out just as good as always and I had leftovers to take to work, too. I made a potato salad to go with it - blog entry to follow!