I'm often stuck grabbing fast food for a quick lunch due to my work schedule. What are your favorite lower calorie choices when dashboard dining is the only option?

Grilled Chicken is always a good choice.
Going with a kid size burger with added tomato's, and lettuce.
Skip the fries
I'd skip the cheese. If you love cheese then maybe have a cheese stick or low fat slice of cheese with you.
A grilled fish sandwich if you can find one.

Another thing you can do is just take your food with you.
A few years ago I'd take glucerna and drink it for breakfast on my way to work.
A sandwich and fruit or a raw veggie such as baby carrots.
I think I've even had a boiled egg during a drive in the past.
Mostly anything that you can hold in your hand as you drive.

I like your idea about bringing food with me. I try to do that as much as possible, but sometimes I'm stuck eating out. I really don't like grilled chicken sandwiches, but I don't mind veggie burgers when I can get them.