DH and I drove from Brisbane to Darwin (8 days) when DS was 6 months and I only used terry squares with a few covers. I had a nappy bucket in the tray of the ute with a lid (water and nappy soaker) and put them in the bucket each day. Every second day I rinsed them in a bath, laundry trough, shower what ever was available where we camped each night. I hung them over a bit of rope DH strung up for a line each night. The terry squares dry quick and if you need a booster pad you can always use an extra square folded over. We were lucky though as there was no rain.