When I need to do a long drive, two things are essential to making it painless: radio / podcast and something to munch on periodically.
My go-to snack is m&ms, but my waistline and dentist are not on board.
Any suggestions for something better?
It has to be something that I can eat easily without looking; that doesn’t melt in the sun and also doesn’t make my fingers sticky (which eg dried apricots or dates do)
Only thing I’ve come up with so far are almonds.
Beef jerky or a step into a Slim Jim. Low carb and saltly, so have some water or a Coke Zero with it. Peanuts are also a good choice.
Or how about apples and bananas? Not low carb but much healthier than M&M’s.
Is this a work thing where you are on the clock? If not, it may be both safer and more pleasant to stop however many hours, that way you can eat pretty much anything without constraints like not being able to see what you are doing.
As per the responses above, fruit could be good, beef jerky, edamame, protein/energy bars, or better yet take a little cooler and pack some actual sandwiches into it.
Twizzlers. No crumbs, salt or sugar residue, no fat.
What’s your impetus for snacking? Is it for the energy boost or is it because you want a mental/physical distraction from the boredom of driving?
I fall into the latter camp. My go-to snack for a long time was pistachios because shelling them one handed took a lot of time and a bag could last forever. Also pretty unsafe to distract yourself that way; a particularly stubborn nut takes up too much active attention.
Nowadays I start a trip with a bagel and some caffeine for energy and I satisfy the need for distraction with a fidget cube. Healthier, safer, and ultimately more effective (for me).
A bag of baby carrots? That’s my go-to snack when I just want something crunchy to munch on that’s not calorically dense and is pretty healthy. Would be easy to eat while driving, and wouldn’t get your hand covered with snack residue.
Anything you eat mindlessly is likely to be bad for your waist. Something like calorie is probably your best bet. Carrot sticks, celery sticks, chewing gum?
Yes it’s the latter. It’s not from being hungry.
Thanks for the suggestions so far. I like the idea of baby carrots.
As I alluded initially, a lot of fruit / veg is too much of a faff for this use case, but baby carrots work
Popcorn, light on the butter/oil or even without any?
Almonds/nuts in general are good; but if you might eat a really large amount of them on any given drive, maybe not so good.
I put a mix of veggies together (when I remember).
carrots, celery, radishes, snap peas.
All crunchy and the flavor variety keeps it interesting.
Grapes. Your fingers might get a little sticky from the sugars, but a dampened paper towel will clean them.
Grapes. And if you have time you can freeze the grapes and they are even more delish.
If you mindlessly eat grapes while driving, they aren’t going to be “healthy”. That’s a ton of sugar.
Yeah, the problem here is that it’s very difficult to square “eating as something to do” with “snacking healthy.” Nuts, for example, are great for satiating you for a while but the OP isn’t looking for that. Enough almonds to keep you occupied for two hours is a shitload of fat and calories.
Carrots and celery are probably the way to go, but they tend to make you pay for it later if you eat a lot.
Popcorn 
or pretzel 
sticks. Easy to eat without looking, not messy, cleans up easily, nibble on them-don’t shove in by the handful-so not that horrible calorically. Throw in a couple 
apples and I’m good for a long day driving. Plus it’s fun throwing the apple cores out the window for the birds and small wildlife to find.
Mini-cut carrots and snap peas.
A couple of KitKats for variety.
Flavored rice cakes are low calorie and tasty. Trail mix which is mostly dried fruit will be good, but not so good that you eat it constantly.
A somewhat unusual choice might be Tamarind Sticks:
It’s kind of like fruit leather with a lot of spice on a stick. If you like things that are spicy, these can be good snacks. They take a while to eat and are satisfying, but you won’t feel like eating them one after the other. You can get them locally from places that have lots of Spanish and Mexican products.
If it’s not from being hungry, then what about gum? Or something to suck on? They may not be healthy, but they have the advantage of keeping your mouth occupied for a while, rather than a few seconds.
I thought that this would be a very typical thing, and the responses would be whether you have X or Y for your snacks.
Instead, it seems I’m a bit of an oddball here. If I knew this was another of my personal quirks I wouldn’t have started this thread 
That is very much NOT the case.
I’ll throw out … lollipops? Keeps your hands free for drivin’ but also lets your mouth - and brain - enjoy a treat.
Bonus points for the “mystery” Dum-Dum pops, if you feel like playing Lollipop Roulette.