I got my sub amp installed over the week-end (Alpine MPR-M350) it fit really nicely under the load-floor next to the factory amp. The remote turn on in my case was pin 10 on the gray connector shown above. Last night I installed a factory sub I purchased from a member here (thanks Jon). The factory sub is basically 2 dual voice-coil drivers. I wired the voice-coils of each in series and then put the two drivers in parallel. This resulted in about a 6 ohm load. The other thing I found that was really handy was the power junction box at the front of the tire well. I found an empty tap, secured the connection with a 5MM nut and added an in-line fuse. I spent some time playing with the cross-over, boost and level. Now that its all hooked up the result is...

Not that bad.. This is a huge step forward over no sub at all. The bass that is there is nice and clean at the volume level I listen at..I'm not trying to win a SPL contest here.. it just does not go very low. This will definitely make the ride to work more enjoyable. I'm going live with this for a little while but will most likely replace the driver with a bigger, stronger JL Audio unit. Big question is a how long is a "little while".. 2 days, 2 weeks, or more... I'm a little pressed for time and winter is coming. I need to figure out the proper driver and how much room I have to work with when I reface the box. The factory sub box is much stiffer than I expected.. I would like to add a 3/4" facing to the front of it. This will take a little work since the front flat of the box has a hump in it.

I would like to thank alpac for the idea and all the help. An as alway, the advise from el_duderino has been extremely valuable.