My nearly 1 year old has suddenly become a horrible whinger in the car. He used to just get fed up and suck his thumb. He'e extremely active and so I think is frustrated at having to be in his car seat for any length of time. It's miserable for all involved !
We always pack a very small bag of toys and little books for DS when we travel anywhere - now he is nearly 2 he chooses his own from the toy/book box before we go out. It doesn't stop ALL the whinging however but he does usually sit quietly either reading or playing, or sleeping.
my ds has always been a terror in the car. hes just an outdoor boy and never happy when hes stuck in his car seat. But, we have a 3 hour journey to our holiday home every 2-3 months so we have to try and get on with it! I have found music/nursery rhyme CDs fantastic! Drive me and DH up the wall but DS loves them. Also I pack loads of mini snacks eg few cheerios in a little pot and travel at hungry times. We sing, which he likes or I give him a small pad of paper and some crayons. If you buy the pads with the ring bit at the top you can tie a couple of crayons to them so they dont keep droping them and getting frustrated.
I get him a new cheap toy every time we do the big journey eg last time it was a mini etch a stetch type thing which was 50p from a tat shop which I save for the megs desperate moments. I have also wrapped a toy I know he likes in a few layers fo tissue paper to delay him getting at it! may only kill can 10mins but can be invaluable.
Im not a fan of sticking kids in front of TV and DS doesnt actually watch it at all but SIL has a portable dvd which hooks over the headrest of the seat in front and she plays her kids favourite DVDs which she says is fantastic on long trips.
We have a break every 45mins unless he is sleeping and let him run around. alot of motorway service stations have outdoor play areas now.