Sorry guys, this just popped in my Junk box. Haven't owned the car for years now.
The problem with mine was there was a fault with the OEM amp not outputting to the sub. So after a few discussions with the dealer it became obvious that they didn't have the slightest interest in helping. So I decided to put a dedicated amp in just to drive the OEM sub. It worked fantastically and turned the system into a very nice sounding unit.
I've owned 4 cars around this time - VW Passat with premium DynAudio, Mercedes A250 Sport with Harmon Kardon premium unit, Toyota Hilux (2018 - not even worth mentioning that heap of crap, sold it 2 months later), 2018 Jeep Wrangler Unlimited (great truck, but couldn't tow the boat!), 2019 Jeep Grand Cherokee. By far, the best sound system was the premium Alpine in the Jeep Wrangler! It absolutely kicks every other OEM unit I've heard. It went ridiculously loud without the slightest distortion with solid well defined bass, amazing midrange, but with just the slightest miss on the very upper frequencies. This system was specially designed by Alpine and they did an exceptional job for a stock system. if you're interested here's a link to a video explaining it:
https://www.youtube.com/watch?v=Kwwhh5R2Mp8