Going on a shorter 7hr road trip- want vegetarian sandwiches to eat on the way that aren't too messy- Suggestions?!

It's so funny that you suggested eggplant- I ended up fixing a potato-pesto salad-ish (the pesto being roasted almonds, olive oil, lemon juice, chives, basil) and slices of roasted eggplant. I sliced up some mozz and salted tomatoes in a separate container- because the passenger can apply that to the already prepared sandwich. My road food ended up being what I had leftover from farmers market- which is (this time of year) eggplant, tomato, herbs4dayzzz. Thanks Nancy! Can't wait until I'm a trusted home cook. ;)

slices of roasted eggplant with (depending on mutual tolerance) raw onion, dark green lettuce, a few leaves of fresh basil and slices of mozzarella, or your choice of cheese on good ciabatta or rough country bread. This is usually made with mayo, but for a long room-temp situation, use mayo, pesto or aioli (again, both of you need to like this or omit from the sandwiches). Last, it is commonly made with sliced tomatoes, but for car picnic, have grape or cherry tomatoes to eat whole on the side. Heavenly.

My family usually packs a sweet and a savory kind.
Savory options :
1. potato filling ( boiled potatoes and peas, mildly spiced and sauteed for a few minutes. ) best made in a sandwich maker or panini press
2. cucumber and butter with salt and pepper ( this one is great with untoasted bread and keeps well for a few hours. Pat the cucumber slices on a paper towel before assembling)
3. vegetables of choice ( and paneer or tofu), grilled or raw with cream cheese and pesto ( or mint chutney if you want to experiment).
4. Sandwiches with Trader Joe's Masala burgers.

Sweet:
1. Apples and jam ( preferably apricot) grilled in a sandwich maker or panini press. Thinly slice the apples, we prefer apples to bananas as they will get a bit soft but not mushy and wont make the sandwiches soggy.
2Nutella and strawberries, but pat the strawberries in a paper towel .

The guys at Court Street Grocers in Brooklyn have a pretty spot on formula for vegetarian sandwiches called R.P.R.P. (raw, pureed, roasted, and pickled). They have a seasonal sandwich called the Uncle Chucky that currently has roasted cauliflower, pumpkin seed romesco (pureed), red onion (raw), pickled fennel, and arugula. They hold up pretty well too since none of the ingredients are too wet.

Pan Bagnat - because it gets better as it sits. Leave out any tuna or anchovy from the recipe and you have a great vegetarian sandwich. You also leave out the egg and add chickpeas if you want to up your protein and have a vegan sandwich.

These can be a little messy if you overfill them, but taste so good you won't mind. But, think about wraps if you want something less messy.