Hi there,
Benjamin is nearly 6 months. I try and time outings during his activity time, which works well now that he is up for about 2 hours. If I can't be home in time for his nap (he naps 2hours in the morning, 2 hours after lunch and 1 hour in the afternoon) then I let him sleep in the pram or car, in which case he only sleeps for 30-45 minutes. I figure one messed up sleep a day is ok every now and then. I try very hard to make sure he gets at least two full naps on a day when one nap gets messed up. I give him toys to chew and play with when we are in the car to try and stop him falling asleep when I don't want him to yet! I talk to him and sing from the front seat too!
We have done a couple of long car trips from melbourne to sydney (11 hours) and my neice (4) was sitting in the back with him and was great at keeping him awake - she sang lovely little songs and tickled him. Maybe you could get your older daughter to play with her if you want her to stay awake?
~ Jaime
