I have the Fender sound system in my VW GTI and the Alpine System in my Ford F150 and I find the ID4 system just fine. Not as good as the other two but it sounds quite good to me. I guess we're all entitled to our opinion....or maybe my ears are shotI am listening to high bit rate MP3 files that sound pretty awful on the VW. Ones with limited percussion and bandwidth, say mellow (Hawaiian) acoustic guitar, do sound OK. Add something with multiple instruments and percussion and the sound goes downhill very fast. I also notice the peakiness in the VW's midrange response.
These same files sounded much better in my previous car.