It is extremely likely that the issue is that the music system is designed around a chipset that only supports 32GB SDHC cards. Changing chipsets late in the game would be a huge endeavor. The 16GB number is probably what is left after apps/code/maps, etc. That's the way my 2012 VW is. Since the chipsets are mostly for tablets and phones - there are few other choices this year. It's not like a PC where you can jest get a bigger drive. I think anyone who wants more storage will need to wait for a hardware upgrade or plug something into USB.