We've had a real struggle getting our 19 mth old DD to sleep well. We've finally just about cracked it. There has always been one exception: the car. She will almost always fall asleep.
Aside from the obvious answer of not travelling in the car (!), or travelling at nap times, we do need a few ploys to try to keep her awake. I've tried feet tickling, keeping the car cool, radio blaring..... What else can I do?!
It's mostly on short journeys (less than 30 minutes) - she seems to think if she has had 10 minutes sleep, then she's good for the day. We do try to plan longer journeys around nap times and allow her to sleep.
TIA