Very nice work! I think if I am going to go for a larger subwoofer then that's the route to take. I might postpone those plans for now and settle for two 6.5" Tang Bands in the doors and use these Infiniti 4" 2-way speakers in the dash:
Infinity REF-4002cfx 4" 2-Way Reference X Coaxial Car Speakers
They can only handle up to 35 rms and the oem amp supplies 40 rms.... Is that going to be a problem?
Here are the Tang Bands:
Tang Band W6-1139SI 6-1/2" Subwoofer 264-832
Any thing I should be cautious of taking this route?