I’ve plugged a tiny Samsung 128Gb usb A thumb drive into the slot in the cubby. This has about 11,000 high quality mp3 tracks on it. This is about 80Gb worth, batch converted from FLAC files on the home HiFi hard drive. Grenny head unit handles these perfectly, organising them by artist and album and showing cover art. Set to start playing instantly when I turn the ignition. I just leave it on shuffle and skip any tracks I don’t want to hear. Looking forward to getting the speakers upgraded and a sub added. I may never go back into the houseThe micro SD card is 128GB of which the "car" music collection is 57GB... so far comprises 223 albums with 3224 tracks. I'm looking to expand that using a 256GB microSD card. There's rich pickings on YouTube with a premium subscription... YT has some wonderful albums from Jazz, classical music etc which are audio only... not bloated with video
IG head unit system can supposedly support a HDD though I've not experimented with it as yet