I take a water bottle everywhere I go. I drink water like a camel so I need to have some with me at all times. And I like to make sure I know what I'm drinking - so many places have unclean water or water filled with "safe" carcinogens.
The iPhone takes decent pictures, but this last roadtrip my DSLR was a huge asset. The photos from our trip are fantastic - I can't wait to get some printed.
I hate stopping for food. Mainly because 99% of the options are unhealthy so I always keep granola bars with me. In fact, there are 2 in my diaper bag at this moment. Kind bars are my jam. So yummy. Bonus: you can pronounce everything in the ingredients.
Sunglasses and sunscreen are givens when driving long distances during the day. Did you know that the most common area for skin cancer/age spots is the left side of your face? The sun beats down in on you while you're driving so wear your sunscreen people!
What are you travel must-haves?