[HELP] Aftermarket Radio Issues 987 (2005)

[AmongstEnemies]

Greetings!!!!

I bought my 2005 Boxster base, built in May 05 within the past month!

Now, don't get me wrong, I love everything about this car.

You know what I don't love? The aftermarket radio!!!! This son of a gun right here, a PIONEER AVIC-Z140BH
AVIC-Z140BH - Flagship In-Dash Navigation AV Receiver with 7" WVGA Touchscreen Display, Built-In Bluetooth®, HD Radio™ Tuner, and AppRadio® Mode for iPhone® 4 and iPhone 4s | Pioneer Electronics USA

Just a week after I bought the car, the radio refused to turn off when I turned off the car and removed the keys, when it had been shutting off with the car before. I went into panic/rage mode and fiddled with the radio for an hour before I took it to a local mechanic...

My mechanic simply turned the battery off and then back on and it was temporarily "fixed" so I let the issue slip back into the recesses of my mind.
EDIT: The mechanic I went to was not an idiot, he did this out of instinct, and told me that it was not a permanent fix. He said that the JAPANESE radio was not meshing well with the GERMAN car.... I'm not sure about the technical details but it doesn't take a rocket scientist to understand that this does make sense. He anticipated me having issues with it in the future and recommended that I simply buy another radio-- now the question is which one is compatible with the 2005 boxster?? ugh

2 weeks later (TODAY) the darn thing failed to turn on with the vehicle... twice... three times. So I turn off the battery, turn it back on and wallah it works again.

So, I have a temporary fix that should theoretically work every time.... or at least for a while. But man that is annoying as hell.

What should I do? Buy a different radio? Try to dig in the wiring and get it sorted out? Take it to the dealership where I bought it from and get their advice? Buy a stock radio? Help me friends!