In my 2010 Prius IV I've always connected my iPhone to Bluetooth for calls and occasional music. I also have an older iPod connected via USB for music. The reason for this arrangement is that I cannot randomly access songs on the Bluetooth connection but I can using USB. It occurs to me that I could get the best of both worlds if I just connect my iPhone to both Bluetooth and USB. But this does come with some consequences (listed below). What do you all do for this? Thanks! Pros One device. Don't have to buy separate iPod. Syncs over WiFi so it's always updated with latest purchases. iPod must use cable. Charge phone while driving. Cons Have to plug in/remove from car every time I enter/exit the vehicle. Notifications such as new mail interrupt music and play over car speakers. May need to buy additional USB cable for home charging.
My early 2010 Prius V was delivered before the USB connector became available. I have an iPhone that I've paired (for both phone & music player) via Bluetooth. Works great, and I never have to take the phone out of my pocket.