It's awful isn't it? DD hated the car too until we turned the seat around at 14 months and even then would get upset on longer trips. There wasn't a whole lot we could do and on one particular trip it was so awful that when we pass the same spots on the road now, it kinda gives me 'flashbacks' to feeling so retched and helpless as DD screamed her way through about half of a 4 hour car journey. The things that did make a bit of difference...
- timing drives around her sleeps but not leaving it till she was over-tired or she'd just cry and not sleep
- stocking up on novel items from the cheap shop, kitchen draws etc to keep her amused. The toys with lights and/or music drive me nuts but seemed to keep her happiest for the longest
- children's music - if I hear 'play school in the car' one more time I will scream but it - and my enthusiastic singing - has got us through many car trips
- if DH is with us I sit in the back and play, sing, tickle, play hiding games, shine a torch around the car/on toes, tummy, hands etc if it's dark, and pass her countless cruskits, bits of fruit, sultanas etc.
- we have taken 5 hours over a 3-hour drive just so we had a couple of big stops to burn off some energy at a park etc.