The volume issues are not coming from the radio itself, but the METRA TOYO interface. My first one lasted about a month and half and started to work intermittently.
Called the company, they denied any problems. When I said it was all over the forums that others had problems, they were speechless. They said it was probably a loose connection on the harness. Wasn't...
Only advice they gave was to return it to Amazon. Good thing I bought it from amazon, cause the return was easy. New one installed about three weeks ago. Used same wires, but new module. Worked right away and seems solid.
As for Entune, grab that over AHA. I have AHA and it is pretty worthless. Apps suck. Never use it.
BTW, if anyone needs a stock unit to max the volume levels, I have a Prius unit that I used. $45 shipped