They stopped adding seat sound for the MY19 leon. I ordered a cupra with seat sound and due to the wltp delay they shipped the car with beats audio. It still has the full size spare and sub in the boot.Think you will find it's minus a sub woofer. The Beats is the branding for the audio range now. The Seat sound system is the one that had the sub woofer but got dropped so you didn't get it. Reckon if you want the sub woofer you need to look to the Ateca Cupra in the UK. Think you might find it has an out board audio amplifier on it which powers the sub woofer. Was always an option on VWs but crossed over to Seat but held back for the Cupra's. You cant specify up.... other Seat markets you can.
(That's why I'd have to go up to a Cupra bling to get what I optioned up on my 2016 Ateca at the time )