Mate, don’t bother. It’ll be an expensive way of getting the sum total of bugger all performance. Use the dough for a fuel filter, oil and oil filter change, you’ll notice more difference and you’re engine will thank you for it.
BTW get the bits and oil from TPS where they will be genuine VW parts (with Quantum Oil) and cheaper than that place the sounds like they’re part of the EUSSR. ATM 5 liters of PD spec 5/40 Quantum is about 15 quid/unbeatable!