I have a 2018 SQ4 with the stock (non Harmin Kardon) 8 speaker audio system which of course is atrocious.I’ve seen HK speaker replacements, HK amplifier, and HK subwoofer all made for Levante all available on eBay for about $900-1000 total. Does anyone know if these are plug and play with my non HK head unit? I’m assuming not. If not, anyone have any suggestions for how to upgrade this crap stock system? It’s my wife’s car so she doesn’t need much of an upgrade for her to be happy with it. Thanks!