I would recommend Custom Auto Radio on Rt 1 in Saugus. They helped me fix a lot of problems with my instal and do an excellent job for a reasonable rate. If you want to install yourself, check out my installation instructions page at
http://empeg.gregdemetrick.com/empeg2_install.html or I can install it for you at a reasonable cost. The unit is pretty easy to get and you should be able to do it yourself with a little knowledge.
Definately avoid Circut City or Best Buy for instalation. They will completely screw it up and have proven this on multiple occasions.
Greg
BTW, the number is 781-233-3037 for CAR