IDiggity

So accustomed to lurking that I accidentally posted this in the general 3G forum first

My buddy noticed the sound in his '08 TL was getting weak, so I'm designing a full upgrade in his car from the stock system (and possibly in my own '05 TL depending on how things go). He might not want to do it all in one shot, so I'm trying to make it so he can upgrade in stages. I'm looking for some comments/critiques/warnings/etc from those of you have delved into the ELS audio system before. Thanks in advance.

Proposed components (sorry for caps and copy-pasta):

• AUDIOCONTROL MATRIX PLUS 6-Ch Line Driver
• Rockford Fosgate PBR300X4 75Wx4 amp
• Alpine MRP-F300 50Wx4 or 150Wx2 amp (4/3/2-Ch)
• Polk Audio db651s 6.5" 2-way
• Polk Audio db6501 6.5" component w/ 1" tweeters and crossover
• Kicker CVT84 8" shallow-mount subwoofer
• PGHHD2C to make my own wiring harness and preserve the factory wires

Plan:
My plan is to mount the amps, line driver, and crossovers with associated wiring on vertical mounting boards in the trunk. I'll use PGHHD2C to extend the factory head unit outputs in the passenger kickpanel without needing to cut off the harness or splice into the wires upstream of it. From there I'll make my own RCA connectors to feed the line driver. I'm thinking of splicing into the factory remote turn on wire to switch on a relay in the trunk for turning on the amps and line driver. I'll use an add-a-fuse to tap into the accessory slot and run a wire to provide the constant 12V into the relay for the amp remote wires. If I understand correctly how these things work, the amps should only get the turn on signal when both the accessory circuit is on and the factory head unit is on. Right?

Stage 1:
Use RF 75Wx4 amp instead of stock amp to run stock L/R front and back speakers. I'm planning to use the trick of connecting the stock wiring for the stock rear speakers to the new amp as the wiring for the front speakers (thanks to this thread). Allow stock amp to run stock center and stock subwoofer for now. Power wires will be run with distribution blocks etc ready for future improvements.

Stage 2:
Upgrade L/R front and back speakers to Polk dBs, including front tweeters. I'm a little unsure how I'm going to run the wires for the tweeters from the crossovers in the trunk - probably up the right side and across behind the dash. It's either that or move the crossovers under the front seats. Stock amp still runs stock center and stock subwoofer for now.

Stage 3:
Replace the stock subwoofer with Kicker CVT84 and add the Alpine amp in the trunk to drive the center channel and the new subwoofer (50W to the center and 150W-bridged to the sub). Wiring trick again (same thread): the stock wiring for the stock subwoofer becomes the wiring for the center channel. Optional: upgrade the center speaker (if not, keep gains lowww).


Interested to know what you guys will say!