I've got a '06 Occy VRS FSI 2.0 petrol on variable service... what oil should I be using to top up with?

VW504.00 specification oil.

Your VAG-dealer or TPS counter will probably sell you Quantum Longlife III or Castrol SLX Longlife III, that's where I get my oil.

Or you could try http://www.opieoils.co.uk/c-1008-skoda-50400-oil.aspx

If you buy anywhere else, just look for 5-30 Fully Synthetic and check it conforms to VW504.00 on the back (most motor factors will have at least one sort that's VW504.00).

Just got myself a litre of Quantum Longlife III for top-ups from Derby TPS.

The part number is ZGB115QLB00500 and it cost £6.38+ VAT/£7.50 inc VAT.