Check out this link: [
www.renntech.org]
This is for the physical installation of an older 2DIN Pioneer nav/stereo system. There is another link for the electrical installation.
The latest Pioneer 2DIN system, that I have knowledge of is the AVIC-Z130BT,which has Bluetooth, iPod, Pandora, satellite radio, etc., etc., integration capabilities. The installation is pretty much the same as the above referenced unit and, at any rate, is not complicated by the MY03 and later MOST interface buss. After having installed two Pioneer systems, I feel the gains in sound quality - just using the head unit's amplifier - is head and shoulders above the stock head unit, even using the stock speakers. Having worked around jet engines and APUs for nearly 40 years, I am not nearly as interested in the various combinations and permutations of amplifiers and speakers that the Pioneer head unit will support.....which are many.
You will probably get a lot of advice concerning the wisdom of having an integrated nav system versus a portable nav system.....keeping your existing radio. The main arguments for portable units are the portability, the ease (and relative cheapness) of updating the data base and the ability of down-loading computer generated routes. ...and more I can't think of off the point of my head. If you want to have an integrated system that has capabilities, both nav and audio, that will keep you entertained and enlightened, I would recommend a Pioneer or similar 2DIN unit.
The author of the link, Trieullionaire, has an installation kit available which makes the installation process relatively painless. Trieullionaire has been ready to assist when customers have had question/problems. I have no financial interest in Trieulilionaire's endeavors.....just a satisfied customer.
Bill