Does anyone know what the Factory deck specs are for RMS power and what is the impedence of the speakers? I'm determining whether to have a stereo shop integrate the factory AMP or to use the deck power. I an external amp is normally preferred but like the new Alpine decks use amps put out 18W RMS at 4 Ohm's. http://www.alpine-usa.com/en/products/product.php?model=CDA-9857
I had an installer wire my factory speakers and amp to a new Alpine head unit. I was sure I got an amp and speaker upgrade too the quality of the Alpine sound was so good.
Doing this avoids any concerns about watts per channel, etc.
New Alpine unit's low level amp-out leads were spliced into the factory Porsche amp. It's doable...
Just don't be the gineau pig for the installer. Call around and find someone who's done it on a 911 or Boxster and is confident they can do it on yours.