Okay, I drive a 1981 Ford Crown Vic, and I have a huge trunk.  I am wanting to upgrade my Digital Designs 2515a to something a bit louder.  I have 1200 RMS @ 2 ohms I can give one of these b!tches.  It will go in a big a$$ ported box, size is not an issue.  I love my Digital Designs 2515A, it is sexy and pretty loud, I am just wanting something a bit better now.  Right now my DD2515a is in 4.26 cubic ft. [Tuned to 36 hz 65.875 Square Inches port  Will be powered by two Directed 750d Strapped [1200 @ 2 ohm]  I may upgrade soon, I am wondering how much would be a fair price to sell these for on eBay, one is in kind of rough physical shape though.  I am thinking something around 1500 watts or 2000. Sound Splinter RL-P18  Digital Designs DD3515D [i really liked my 2515a subwoofer]  I don't even know price of this woofer? Elemental Designs 13Av.2  [Kind of skeptical on this, and I want a 15" instead of a 12", this sub doesn't look to bad, but eD has pretty chitty business practices from what I have heard.  Besides it doesn't really stack up w/ some of these subs] TC Sounds 15" TC-2000  Fi BL15 throw Audio Que on the list too. For the enclosure I can give it about 10 cubes max in the trunk and still be able to mount my spare tire  Unsure if I want to go down to a crazy low tune (29-30) or if I want to put it up about 35.  I know the RL-P18 is said to be great in big ass vented enclosures w/ low tunes. Sound deadened everything almost, 1 door is left along with the roof.  eDead/Second Skin Sludge combo.  5 layers of eDead in the trunk w/ a thickass layer of Sludge over the top.  Floors inside the car have 2 layers of eDead.  I need to get some more sludge or spectrum spray.