Here’s the AI response to your tyre pressure query;
For a Mk7.5 Golf GTI sitting in storage for 6 weeks, inflate all four tyres to 45 PSI (approx. 3.1 bar).Inflating to the upper limits of the tyre's recommended range helps prevent the tyres from developing flat spots caused by the weight of the vehicle resting on the same patch of rubber for an extended period.
It might also be worth putting the battery on trickle charge and as you’re going to be parked in your garage on a level surface, maybe consider disabling the parking brake so the brake pads don’t stick the discs. If you don’t disable the parking brake, ensure the brake pads and discs are dry at the start of the 6 week period to minimise the risk of the pads sticking to the discs.