iPhone to USB input in the car...

I have a 2018 VW Sportwagen with audio inputs for AUX, SD card and USB A. I normally use an 128GB SD card with a mix of AIFF, ALAC and MP3s for road trips but after reading your message I tried putting the SD card into a USB card reader and plugging it into the USB input. It works perfectly. No idea if that would work with the Mini and it does have limitations in terms of song selection/navigation but it’s perfect for me. I have a ’Roadtrip’ playlist on the card with 1,300 songs that I put on shuffle and just drive.
Reader like this -- https://smile.amazon.com/SanDisk-UHS-I-Card-Reader-Sddr-C531-Gnann/dp/B07HB866XN/ref=sr_1_14?keywords=USB+SD+card+reader&qid=1560691021&s=gateway&sr=8-14

Thank you both for the feedback...

i currently have a 2017 Mini (with an Aux In), but already ordered a 2019 as my lease is getting to the end.

The new model comes with 2x USB ports instead of the previous USB and Aux ports,

Phil, it would be very disappointing if the system only plays MP3s! Is that confirmed for new 2019 BMWs?

I’ll try to get me more details from my Mini dealer, but can’t comprehend the reasoning behind it, especially that the industry is moving towards higher quality formats...

and thanks for the tip about AQ Jitterbug, it’s worth trying it out when I get the new car. 

Thanks!

I have an HK system and think the SD Card or USB with 320 VBR MP3 sounds as good as the system speakers & amps are going to do.

If you want better you are probably going to have to put a whole system in.