I only pull into the fanciest rest stops.
In city traffic or highway? I can get anywhere from 1 to 5 miles per Polly.
I’ve done many road trips where I’m either in a remote area where I’m lucky to find a gas station, or I’m in a hurry to get to my destination so I only stop for gas, so I’ve been there.
My go-tos are peanuts, beef jerky and something to drink that’s lightly caffeinated and not too sweet-- Arizona Green Tea flavor iced tea is a good choice.
They’ve been around here in the PacNW for quite some time. They’re also one of my go-tos to have on the boats when we’re fishing 
Yeah, I do a lot of fly fishing trips and end up driving back late at night. I’m looking for something that’s not goop in styrofoam and non carbonated. OJ and peanut butter crackers is another good one.
Diet Coke
Pizza combos - I prefer the cracker-type outside rather than the pretzel (but I’ll eat them!)
Pringles (regular) - the can fits perfectly in the cup holder
Twizzlers
Jr Mints
Oooo, chili cheese Fritos! Forgot about those! When I was in Dallas they had Tabasco Fritos, I lived on them while I was there…
When I was single and driving distance I’d take a bag of peanuts and raisins to munch on or trail mix along with a 2 L container of water. But since I’m at the Sev I’d still go with a slice and Doritos.
When I used to live in the country, I had about a 45 minute drive from town. I’d often buy these at the ice station (convenience store) and eat most of a bag during that drive.
https://www.fritolay.com/sites/fritolay.com/files/sabritones-chile-lime.png
Possibly not readily available outside areas lacking a sizeable Hispanic market. They’re supposed to mimic the texture of fried pork rinds, but they’re made of wheat. They are SOOOO hot! You have to keep eating them to keep the burn from catching up with you. I’ve actually had damaged tissue on the roof of my mouth the next day after eating a whole bag of them.
Combos (pizzeria style) or Pringles (sour cream & onion) are my favorites. If I feel like I need sugar, probably a Milky Way Midnight (if they have it) or a Snickers.
A perfect meal.
Orange Hostess cupcakes, some beef jerky and Coke zero. It’s the only time I would eat this stuff. If they don’t have the cupcakes, some cherry Pop Tarts will do.
I’d like to point out the principle that Road Calories Don’t Count.
I eat very healthy at home. Practically vegetarian, small portions. But when I plan a road trip (esp. a solo one), I know I’m going to be mapping out stops at Cracker Barrel (for massive breakfasts, inc. grits!) and Culver’s (for bacon butter burgers…mmm…).
And fun snacks at all gas stops, of course.
I do normally follow that rule, as a subset of ‘vacation calories don’t count’, but dammit, I want QUALITY calories, and 7-11 grub just normally doesn’t meat (heh) the standard. Now there are plenty of guilty pleasures in roadside stops, but we must stay within the limits of the scenario set by the OP, or the hijack wouldn’t end anytime soon.
On a slight tangent, but still within the spirit of the OP, I wanted to share what my choices would have been years ago, when I was a child/pre-teen as a passenger in the family car, back when I could eat that sort of stuff and not have a sugar crash, heartburn, or any other issues. I used to love (!!!) getting the ‘fresh’ popcorn that a lot of trucker/large scale gas stations used to have. Not because it was super good, but because back in the day, the only other time you got popcorn was movie theaters. And best of all, it was a lot cheaper than most of the snacks.
So if dad gave me and my brother $5 to get snacks to shut us up for the next few hours of a drive, my brother would spend his half on Coke, sunflower seeds and LPDs (Little Powdered Donuts), I’d get a huge (well at 12) bag of popcorn, Sunkist soda and 2 Milky ways.
M&Ms or Snickers.
Like seal flipper pie, the name alone has been enough to make me disinclined to try them.
Mountain Dew and Cheez-Its or Cheese Nips crackers – long-haul driving only.
Seal flipper pie is okay. A bit greasy.
If it’s the middle of the night it would be one of those Starbucks double shot energy drinks, the 15 fl. oz kind. Not because they ever give me any energy, I just like the taste. And a pound cake/crumb cake of some sort. The middle of the night is way too late to deal with a fully loaded dog, which is what I would get during the day, along with a cherry Dr. Pepper.
A package of bologna, hot dog buns, and ranch Pringles. Pringle and bologna sandwiches are pretty good when you don’t have condiments.
Oh god. I had to quit these cuz I got addicted for awhile. Even just running to the bank I’d stop at my corner gas station to get a bag.
Ah <extends hand> One of Us. 
They’re great, aren’t they? It helps if you love pain.