Sure you could run through a head unit. That's the easy way to go. Just stash it somewhere. (As long as the head unit allows hand control of the iPad/iPod).
iPhone 5s (iTunes library/iTunes radio/Waze, etc) to Airport Express via AirPlay. Aux out of Airport Express to Helix A4S Competition. Micro-Precision 5.28 tweeters, Gladen Sub, and Dynaudio MW152 midranges. Jehnert Door Cards and mid-bass'.