The first one seems to take place in Australia (they fly over Sydney at one point), and involves a flying bus, a house in the middle of nowhere and a treasure, I saw this in French, not in English although I know it was dubbed into French. I think it was around 1981 or 1982 that I saw it, and I really want to see it in English from the beginning.

The second movie I saw around 1985, it involves two kids and they chase this animal into the forest after it's stolen money, all the animals they interact with are animated, so it's a mix of live action (kids, forest, etc) and animation (animals).