Agree with the weather aspect.......we have used capsules for Olivia and Charlie and will do again for B3, but with Olivia it was a pain because she was in it FOREVER (cos she is so tiny) and we were in the heat of the NT, and the air-con doesn't circulate into a capsule.......so she would wake all sweaty.

(That said, we were in Darwin, so all car trips were short anyway)