Hi Chokkie
My current car only has a usb facility, and it has driven me nuts. I`m no Luddite but prefer to have a CD player for simplicity as I also make my own for the car. The problem that no-one talks about is file management for SD / USB to this day no infotainment system will accept flac files let alone hi-res flac files which is madness as it is only a small codec to include!
So, now also most cards / sticks are formatted with NTFS which is fine if the system allows that, I have to format mine to exFat to play anything, which is the most preferred for multiple files which are constantly written / rewritten according to experts! But occasionally especially if you have made your own folder with different tracks it goes into meltdown and repeats the same track or hides the file altogether.
As I said this has been a nightmare, so much so I have actually bought a new car myself (delivery hopefully this week) and I made sure it has a CD player (also plays wav and mp3 files) but also has 2x usb inputs so fingers crossed will suit my needs.
Sandisk are the SD of choice, but you dont have to go mad on the size, an 8gb or 16gb will be more than enough otherwise if you put a 32gb with hundreds of tracks you will be forever searching for something!
Enjoy your new car, sounds like you are getting a VW or Seat