To get goodwill to replace a high level brake light on my spoiler I put I got the dealers to back me up saying it was a stupid design, a full service histrory, pointed out that I bought all my consumables (ie oil / washer fluid etc) from the stealers, that half my family drove VAGs and how disapointed I was with the brand etc etc. I got goodwill for half the cost ....
Without a full histroy, and if you didn't buy it from a stealers I think you are on your own to be honest

Even if you do get a 'stamp' in the book, servicing is recorded on the dealer network system. So they will know you aren't on the level...