Just taken delivery of my new 2024 A7. I really am uncomfortable not having a proper spare wheel, just the naff repair kit. In the boot in the space where the spare would go is the sub woofer. If I take that out to put a space saver spare in will the sub woofer still fit in the space ? Obviously the foam and pump would need putting somewhere else . Has anyone tried this? Would it be worth posting this on the A6 thread? Are the cars similar enough ?

You could have the sub moved but this will void the warranty regarding the sub. A spare wheel from an A6 should fit. Might be worth buying one a d fitting it in the boot without the foam as you suggest to see if it fits over the sub.