If I connect my I-phone to the USB plug in the saddle bag it works great, clear and loud, but I assume it will run the phone down. Yes I use a memory stick to play some music I got free somewhere but the I-phone has purchased and better music on it so is preferable. I plug into the little small pin plug in the front unlocked cubby and it does not play very loud, no where near as loud as from the USB or the radio. I plan to possibly move the USB up to the front where I have a power outlet and can keep the phone charged. Eventually will be hooking up a Zumo 590 and will need all plugs I'm guessing for GPS and phone. The 590 has it's own music and will play anything accessible with the phone via blue tooth but still need to be able to charge. My question is about the sound volume when plugged into the small plug. Am I doing something wrong or something wrong with my tie in? Thoughts?