So I been reading through some threads and there are several people who have added a double din in their TL right below the A/C controls where the actual OEM radio is. Obviously there is some custom work but it does not look too extensive. The double din trim rings seems to do the trick especially for the Alpine double din units.

A lot of you have lost either steeering wheel controls, bluetooth, or something else.

Wouldnt you be able to add a double din and keep your steering wheel controls, bluetooth, ect... if you were just adding a double din and bypassing everything?

What if you just add a double din, but only use power, 12v switched, and ground to power up the headunit. You would run RCA's to your amps for sound, and then run speaker wire from your amps to your upgraded speakers.

By doing that, your essentially bypassing all of the factory wiring, factory amp, etc.. you would still have your OEM Nav because that nav voice comes through the center channel speaker. Your bluetooth however... more and more headunits are coming with bluetooth anyway.

wouldnt it work, or is it not that simple?

 

I'm really curious too! I found this online... idk if it'll help. I'm new to this stereo thingy.
http://www.carstereo.com/forum/showthread.cfm?tid=14600

 

You could essentially not loose anything and keep the stock amp/sub and original wiring if you like. There is a kit you can get from Krankitup which will allow you to tap into the amp and sub wires to keep your factory amp/sub. In the same kit, there is a bypass to connect the center speaker to your navi. You can order a module that will allow you to keep your steering wheel controls and lastly, most double din decks come with Bluetooth. So yea very possible :-)