My experience is that unless you have the remote and the DVD player set out of reach of little hands, you spend a lot of time fixing it. My DD has a DVD player for the car (family use) and really it only comes out on LONG trips. It's preloaded with Shaun the Sheep (her favorite car DVD). At 16 months, I'd find other ways to entertain the kiddo.
My DD could take or leave the DVD player. I drove 3 hours to my cousin's house and it never even came up.
If she gets too attached to the TV, then you turn it off. Let her cry a bit, she'll get past it. We tell DD that the TV has to go take a nap and it goes off so she'll find something else to do.
I found that when my DD went through a phase of tantrums, so did all the babies of a similar age. And lo and behold - it was around the time they learned to crawl or walk. They probably don't like to be strapped in! But they have to be, so bring some soft toys, or special things she only sees in the car. A small cloth bag with something special for her to discover...worked for my DD. And music. Often soothed the savage baby.
Here's something to bear in mind - kids are different. There are generics that work with most, but unless you're a real screw up, you'll find your path to her 18th birthday just fine. Don't worry if YOUR kid didn't get the exact memo as the books. Don't fret every detail. Make informed decisions and if you mess up, say you're sorry and move on to something else. Don't go through parenthood expecting a disaster.