Some owners will already be very clued up, expert about many areas of GTI ownership.
Others not so much.
I know a thread on the VWROC forum where different Tyre types etc are discussed and any current Offers or Bargain buys can be shared with other owners. It can help an owner from being stung at the Tyre depot, for want if a little knowledge and pre planning preparation.
But this will be of little value to owners who already know lots of things about lots of things.