Plus, just think of all that oil spraying the underbody whilst you're bombing down the roads! Rust???? Bah!!!!!saves me changing the oil though as it does it itself every 3 months.
Without having seen the problem myself, I still believe (from previous discussions with Adam ) that either the camshaft seal (dizzy end) or the sump gasket, is the culprit! Especially considering that Adam changed the belt end cam seal, and IIRC the GT has had a different sump fitted at some time, possibly from another model (16V?) which required a "spacer" (or not....I can't remember offhand).
Anyway, just a thought!