You can also cook or grill sausage or brats ahead of time and eat cold with mustard, cook cheese tortellini and eat with no sauce and cold (toddlers like this one) or with salad dressing. Individual size hummus containers for dipping pretzels, carrot chips, crackers, tortilla chips, or the same but individual size guacamole containers (both available at Costco if you're a member). Grilled bone-in chicken or fried chicken is always good cold (I've eaten bought some at KFC or other places to take because I think it's better than many other fast food options and is fairly inexpensive). I try to keep things from getting too messy so no yogurt, saucy things, etc.

Berries. Everything is fun with berries.

101 Picnic Dishes to Make in 20 Minutes:
http://www.nytimes.com/2008/07/02/dining/02mini.html?_r=0

We keep a "grab bag" in our car with individually portioned snacks. Kids get to reach in and grab a snack-they love it.

Roast a chicken ahead of time, cut into pieces. It can be eaten cold as finger-food. Goes well with pasta salad and watermelon.

Mixed platter with sliced salami, crackers, hard cheese, olives and pickles, veggies and hummus.

Are you eating inside the car or will you really picnic outside of the car?

I'd take a cooler with:
- sandwiches w/o mustard and mayo (get single serving packets from Panera to take with you or something)
- chips
- cut veggies (carrots, peppers, cucumber) and a dip of some type (ranch, balsamic, etc...)
- cookies
- juice and/or iced tea

Or, honestly, I'd be inclined to stuff a cooler with drinks, grapes, chips, cut veggies, and cookies and stop a McDonalds or something to get 4 $1-menu sandwiches.

we make pasta salad

I can pack the cooler with lunch meat and pbjs.. But seems so pedestrian, help me think outside the box. Fast food stops are not really in out budjet this time, how can we make picnics seem like a treat?