Please advise...2008 G35x Sedan...with bose...non-nav...I want to upgrade the following

1. Replace the stock bose amplifier with a 5 channel aftermarket amplifier (not too large - within the range of 50x4 / 150x1)
2. Replace the stock front speakers and stock rear speakers (unknown size)
3. Replace the stock bose rear subwoofer (unknown size...I understand that a boxed sub will sound better but I am not willing to part with the trunk space)

I have some questions...

1. What size front speakers should I be looking for? I have heard 6.5" woofer / 3' mid / 1" tweet but also 10" woofer / 3" mid / 1" tweet.
-------- If it is in fact a 10" woofer...is there a spacer kit I can buy which will allow me to install a 6.5" component set
2. What size is the rear subwoofer? I have heard 8" and 10".

Am I missing any steps in the installation process below...also...I am unsure of step 3...is there enough space to fit an aftermarket amp in the location of the stock bose amp...

1. Replace front and rear speakers...utilize stock wiring from amp to speakers (modding may be necessary for spacers / tweeters / crossover location)
2. Feed the amp's power wire through the rubber grommet within the firewall...under the carpetting...down the passenger side of the car and into the trunk through the rear seat
3. Mount the aftermarket amplifier in the same location as the current stock bose amplifier (???)
4. Connect the stock bose amplifier's input to an LOC
5. Connect the RCA output of the LOC into the RCA input of the aftermarket amplifier
6. Transfer the stock bose amplifier's speaker outputs to the aftermarket amplifier speaker outputs

Thanks...

 

I also would like to see what needs to be done, Having a heard time finding out this info.

 

To answer your amp question there is a 5.1 alpine digital amp that is a direct fit to the factory amp. I was going to have it installed in my car but season tix for football took priority. I also ran my power wire down the drivers side only cuz that was the easiest hole i found to go through. Hope that helps keep us posted.