As seen online:
“The below foam and jack kit for the Fabia MK3 includes everything, except for the actual spare wheel...which you can purchase separately.
Thjs kit normally uses the standard Fabia MK3 15" wheel which is 185/60R15 fitted to a 6Jx15 ET38 5/100 57.1 rim...normally steel if it's a spare wheel.
The foam and jack kit can be ordered from any VAG parts department by quoting OEM part number 6V0093860B. The Czech price is about £49, but the UK price can be slightly more...perhaps up to 20% more or so.
6V0093860B
https://eshop.skoda-auto.cz
Google "alcar 7760 mytyres.co.uk" to find a listing on mytyres for an Alcar 7760 6Jx15 ET38 5/100 57.1 steel rim. Currently priced at £43.47 including shipping to the UK from Germany. This is an aftermarket steel rim that exactly matches the original Skoda steel rim.
Alcar are made in Switzerland, so as you would expect are OE quality.
This steel rim can be ordered from mytyres with a fitted tyre of your choice. One option is a Continental UltraContact 185/60R15 84H.”
— from Škoda Fabia mk3 spare wheel size help - Skoda Fabia Mk3 (2014-2021) - BRISKODA as of 20 June 2025