OK. Today I have carefully removed my air filter housing and it only has two grommets and projections on the base (2 litre V6) and the front connects to the plastic oval pipe from the shannon tube.
I have located the auto transmission filling point (aren't they small!) and put a smear of rubber grease on all the push pull and hose connections ready for the fluid change.
I've also found the cause of my induction "roar" at certain revs. The jubilee clip connection to the induction was nipped at the bottom leaving a gap on the rubber pipe. All tidied on return and I now have a quieter induction - bliss!
Mike