Charmaine - i think there is a big distinction between using a DVD on long car trips (we probably just fought more in the back seat and heard more of the "don't make me come back there" comments) vs. watching DVDs every time you go out in the car. we also play I spy, sing lots of songs, talk, look at books (i can do anything in the car and so far my kids can too without getting car sick (my sister used to barely survive car trips).
We are gearing up to head to sydney next thursday doing about 7 hours(+ rest stops) day 1 and 3+ hours day 2 (and doing straight thorugh drive on way home). in addition to the DVD i am cutting out felt shapes for them to add to their felt sets we will bring, have art supplies, I spy type books, a dinosaur building kit, more felt sets LOL, some new books, Angelina ballerina CD with 10 stories, matching card games and some other small toys. we rotate as we go and i think they appreciate the down time where they can relax and watch a show, but don't actually have to stare out the window.
not debating the issue or feeling challenged - just explaining how i think if used appropriately it is a great modern addition just like people being able to take their IPOD out with them and have many CDs to choose from instead of the old days when my parents had only an AM radio and then an 8 track and then a cassette tape in the car... the music available certainly improved our journeys.