I haven't dug into all the nitty gritty details yet about the 3g's integrated Nav.

Here is what I am thinking.

Replace both front mids and tweets and the sub, and power all that off a 4 channel amp. But still take input from the factory unit?

Keep the OEM amp connected to the rear and center channel speaker.

Anyone see any holes with this plan that won't work or snags?
Difficulties?

 

check my thread "mild grade fever" similar concept. there are several intricacies that need to be addressed

 

This is exactly what I chose to do. Check out my thread "is this possible" for some Q and A.

I decided to take the pre amp signal and was advised to use a line driver to boost the weak stock signal from the headunit. One issue I have read about on these forums is the introduction of noise with the use of a line driver. It's still a work in progress which I hope to complete in a couple weeks.