Hi William & Leslie,
I know your posts were quite a while ago, but was just wondering if you have managed to source the parts needed to fit a space-saver spare wheel into your A4s. I have a 2019 A4 Avant and have very recently bought the polystyrene tool holder (with tools) from bargainhunter 3210 on Ebay for £54.99 + a brand new, original spare wheel with tyre, again from Ebay, seller: dalin_7124 for £139.00. Both these items are genuine Audi/VW parts bearing all the correct numbers. An alternative source for the tool holder is from Ebay seller Red Brain, there are many sellers offering the spare wheel. I have not yet got around to fitting the kit since the weather has been too cold and damp! 🥶
As an after thought, I also enquired through my local Audi dealership as to whether or not I could fit a spare and was told it depends. If your car has the superior sound system, then no, cannot be fitted as no room due to sub-woofer, I think.
Hope this may be of some help, albeit a bit late, perhaps! 😀
Regards,
Chris