Coolant Should Be Easily Traced !
Not trying to sound arrogant but a coolant leak should be quite easy to locate seeing as though its bright green or red but green in the case of VS's .
Its called the oil filter adapter, its held on by 3 bolts that are accessible once the oil filter is removed.
The centre 1 is a a bugger held on by loctite !
Also a new gasket is under $5 from holden
Hope that helps someone would've helped me lol