Ok guys...here is my setup...

2001 S2000

What I have installed already from a while back:
Stock HU
MB Quartz 6.5 components in the doors
Us Acoustics 100w x 2 for the MB Quartz


What I am adding to the system:
Apline CDA-9885 HU
S-Pods with Infinity Reference Series
Sirius radio
Modfry DCI


I am just going to run the Infinity's off the HU because they are right behind my head...don't need those too loud.

Ok now I want to buy a WLaurent box for the tool well. I am stuck between a Alpine Type-R 10" or a 12" that he sells with the box. How much difference is there sound and power between a 10" and a 12". Also, which Alpine amp should I power this sub with...the MRP-M450 or the MRP-M650? Why would someone run in 2 ohm vs. running in 4 ohm mode? Which mode would be better in my situation....I don't want stuff melting back there though! Obviously I would want the run the MRP-M450 because it is cheaper and smaller, but would the MRP-M650 be that big of a difference? I want to hear the bass in the cabin of course! Hopefully someone has run into this situation before. Thanks guys for making this site so informative!