Thanks Biju- Well, that clears up why the mechanic at the dealer had an issue with the Royal Purple. He probably had to follow certain "rules" layed down by his bosses. Which doesn't mean Synthetic is bad, surely it's better. But ... I guess it might affect the warrantee though.

Do you know if putting non-dexron III in voids the warrantee? I think my power-train warrantee is still good til this October. Maybe I'd better wait.

Also: I'm assuming flushing is the way to go if switching to synthetic. Is this true? (pretty obvious I guess)