I just read NS’s email regarding the extortionate cost VW charged for engine oil. I suffered similarly with Audi a few years ago, being charged for 18 1/2 litre bottles. This year Audi wanted to charge me £17 per litre. My solution was to ask them what oil they used and then I bought some on the Internet and gave it to Audi to use during my car's service. This saved me over £50 and was sent post-free. Only downside was that Audi kept the 0.8 litres left at the end whereas normally they give you the excess "complimentary" (though, in fact, you've already been charged for it).