Nice.  I used to be

I Had MB Quart Components with pro Crossovers
Precision Power Amps
Eclipse Head Unit and Eq
3 JL Audio 8W6 Subs.

Nowadays, i think the family gets more benefit from having a nice Aperion home theater system in the living Room.  Also, i think that big sub enclosure would take up to much room and not leave any for family vacation packing, how do you fit luggage in there for trips?  Have you ever thought about using a combo of tweeter, 5 1/2 midrange, and 8 inch bass driver components in the door panels?  Of course you would have to do some modding. But that should supply you with plenty of full range sound without the need of a subwoofer. The key is the installation.  making sure your door is sealed appropriately and is treated for vibrations as well as placement.  You wont realize the speakers true abilities unless it is enclosed, placed and sealed correctly.

  i really never liked subwoofers in cars they just don't seem to match the sound you get out of a sub in the living room of your own home, besides, how much bass do you need for the interior of a car?  I have a 10" Sub that fills my entire living room.

However, We do have an aftermarket overhead Audiovox DVD, Pioneer Head Unit and set of JL Audio 5x7 speakers in our Family minivan.  It sounds ok, but it's hampered by speaker placement and the lack of an amp.  But she's alright