I'm not sure about that being the case with Apple car play as well as I've not tried it, but for sure when using the radio pressing down goes to the next preset and up goes to the previous one. That makes sense because the channels are kept in a vertical list on the infotainment screen and maybe they just carried that concept over to the phone interfaces as well. It took me a bit to adjust as well as I figured up would mean next also, but I starting thinking about it as it is on the screen in that vertical list starting at the top and working down. For whatever reason this visualization helped me to work it out in my mind. No idea why it's different though, unless they changed it in the more recent software or they just happen to wire them differently between the two models.