albertporter,
I am by no means adept at computers beyond turning on/off and a few more very-low-user actions. I learn the dumbest way, from own experience, so I deducted a few things from your story and my experience. CarPlay has to be used via iPhone. SD card probably goes some other way and the fact that car has Carplay does not mean SD card will behave in any similar way. My iPod was bought in May 2015 and I believe it is 5th generation. My car was bought in December 2015 and, surprise, iPod cannot connect via Carplay at all. I am not sure about now, but iPod simply did not come with Carplay. That is just so you do not buy an iPod and find out it is not Carplay compatible. On the other hand, just being an USB device works great. As far as USB devices go, I did connect Solid State Drive and it worked well. I also have a SONY NW-35 (small $200ish Walkman) and it connects and plays via USB without a problem. It becomes just another SSD connected via USB. Android phones have something parallel to Carplay (Android Auto, I think) and they frequently have expansion slots for more memory. However, I got an impression that you have an iPhone and, if you ever connect it to the car for phone purposes, I wonder if you would be able to connect another Carplay/Android Auto device at the same time. I would not be surprised if the car thought you were connecting two phones as it might see them that way.
As far as functionality goes, I hope your Bose is as accomodating as VW Fender system. Whatever I connect (SD, iPod, Solid State Drive) it shows album covers and songs and all that it is supposed to. It does not matter what media it is coming from. There are some minor issues (albums with same name, at least first 20 letters or so of it become clumped as one album so you have to change metadata a little bit, think "Greatest Hits", "The Best Of", etc.), but in the end it works out like an unbelievably convenient system. The only unexpected detail that does not work with my SD card is voice control for songs. If I try voice control to pick the song from the whole SD card, it says there are too many songs. I believe I have 12000-15000 and that is what confuses it. It has no problem picking albums or artists via voice control and then picking the song from that album.
These are just a few of my observations. I would still try with SD card and FLACs. I think that dBpoweramp even has some free trial version, but do not hold me to it. You need it for the simplest operation it can do, anyway.
I am by no means adept at computers beyond turning on/off and a few more very-low-user actions. I learn the dumbest way, from own experience, so I deducted a few things from your story and my experience. CarPlay has to be used via iPhone. SD card probably goes some other way and the fact that car has Carplay does not mean SD card will behave in any similar way. My iPod was bought in May 2015 and I believe it is 5th generation. My car was bought in December 2015 and, surprise, iPod cannot connect via Carplay at all. I am not sure about now, but iPod simply did not come with Carplay. That is just so you do not buy an iPod and find out it is not Carplay compatible. On the other hand, just being an USB device works great. As far as USB devices go, I did connect Solid State Drive and it worked well. I also have a SONY NW-35 (small $200ish Walkman) and it connects and plays via USB without a problem. It becomes just another SSD connected via USB. Android phones have something parallel to Carplay (Android Auto, I think) and they frequently have expansion slots for more memory. However, I got an impression that you have an iPhone and, if you ever connect it to the car for phone purposes, I wonder if you would be able to connect another Carplay/Android Auto device at the same time. I would not be surprised if the car thought you were connecting two phones as it might see them that way.
As far as functionality goes, I hope your Bose is as accomodating as VW Fender system. Whatever I connect (SD, iPod, Solid State Drive) it shows album covers and songs and all that it is supposed to. It does not matter what media it is coming from. There are some minor issues (albums with same name, at least first 20 letters or so of it become clumped as one album so you have to change metadata a little bit, think "Greatest Hits", "The Best Of", etc.), but in the end it works out like an unbelievably convenient system. The only unexpected detail that does not work with my SD card is voice control for songs. If I try voice control to pick the song from the whole SD card, it says there are too many songs. I believe I have 12000-15000 and that is what confuses it. It has no problem picking albums or artists via voice control and then picking the song from that album.
These are just a few of my observations. I would still try with SD card and FLACs. I think that dBpoweramp even has some free trial version, but do not hold me to it. You need it for the simplest operation it can do, anyway.