Thanks fot the replies guys - I knew I could count on you Rick!
Basically I have about 2.5 litres of Selenia left and could only find a 4 litre bottle of castrol, which the dealer says isnt enough for an oil change, so I was hoping that i wouldnt have to go out and buy another 4 litre bottle of castrol!
I have hopefully sold the GTA anyway but I just didnt want to screw the car for the next owner if I could possibly help it!
I am now on the look out for a nice sportswagon JTD, fancy a change rick?!!