Hi
Scott - I'm assuming that your mean
iPad Mini (above in bold) - first, if your stereo has USB ports and your iPod Nano works, then I would assume other iDevices would also; now whether this would provide enough wattage to charge an iPad Mini, I cannot say - you would need to check w/ the manufacturer of the sound system and/or the manual.
For myself, we bought a new Camry 2014 last spring and I can play music from our three iDevices (old iPod touch, iPad Air 2, & iPhone) - there are 3 input choices, i.e. USB, mini-stereo jack, or Bluetooth - when my iPod (or iPhone) is plugged into the USB port, the devices show charging; however, when the iPad Air 2 is used, NO charging is shown - this device typically uses a 10-12 W charger, so I'm assuming the car's USB port is putting out half of that wattage - an iPad Mini requires less power so would likely charge (even my iPad would get a small trickle charge). Dave