I'm installing an 8" subwoofer in my 2006 Scion XA, my question is I bought the iPod upgrade when I bought the car which came with the Pioneer DEH-M8157 head unit. Will this head unit have the hook ups to install the subwoofer? Thank You.

 

You'll need to get a line out converter that will tap to the speaker level inputs on the stock stereo and allow you to add a sub via RCA.