The ONLY option for your friend is the PhatBox from PhatNoise. They currently don't support Sony, but it's on their short list. If your friend had a Kenwood deck he could install it in no time at all (or even buy the Kenwood version of the same box from Crutchfield).

Is it as good as the empeg? Not by a long shot (in terms of features and function - sound quality will be good).

Take a look at the matrix I put together a little while back: www.mypocket.com/mobilematrix/index.php

Bruno