I've spent the last two days searching the forum and visiting car audio shops trying to find the most cost effective way to improve, replace or upgrade the Bose system. I wasn't able to find a definative answer for what I'm looking to do.

I already purchase a set of Infinity Kappa 63.5i's that I'm going to put in the doors like some others have. Only $100 there, so it's worth a shot. I'm thinking that if I'm not happy, stage 2 will be to replace the head unit and the rear speakers. In this stage I would drive the speakers off the HU power.

I want to do the work myself to keep the cost down and buy reasonably priced components off eBay. To do the work myself, I can't be rewiring speakers and things.

Here's my question: Can I buy a new headunit, plug it in to the factory wiring harness (Metra harness or similar), replace the speakers and some how bypass the external 4 channel Bose amp so the power to the speakers will be coming from the HU? Is there a harness that connects the input and output of the amp together, essentially bypassing it? If not, is it easy enough to spice the necessary wires together to bypass the amp.

Stage 3 would be to add an amp and a new sub. Stage 4 would be to add an amp for the front speakers. Stage 5, would be to buy top of the line components and so on and so on... If it's anything like my home theater system, it will be a never ending process.

For stage 1, I'm thinking of the Pioneer Premier DEH-P740MP http://www.pioneerelectronics.com/Pi...,21409,00.html which I can buy online for under $300. I'll also get a set of Kappa 62.5i's for the rears to match the 3-ways I'm putting up front. Total cost for this stage would be under $500 and I think it would be a huge improvement.

 

This is basically what I am looking for, too bad it's for a Ford:
http://www.audiowarehouseexpress.com...sp?mdl=70-5513

I emailed Metra asking if they have any plans to make a similar item for the Z.