Well, a double platinum plug should go 100K and I believe toyotas come with Iridium plugs which are even better than the platinum. I know that Toyota tells ya to replace them at 30K but thats ridiculous. Those plugs are like $10-$15 a plug. A regular ole plug will go 30K. As far as the fluids, it depends, on my 02 Highlander you supposedly never have to service the tranny fluid or so the owners manual says. On my 05 Tundra it claims to replace as necessary whatever that means. I figure I'll change mine at 30K then at 100K.